DESIGN OF BAND NOTCHED ANTENNA FOR ULTRA WIDE BAND APPLICATIONS

ABDINASIR SULIEMAN OSMAN (0833359)SUPERVISOR: PROF.DR. MD. RAFIQUL ISLAM

DEPARTMENT OF ELECTRICAL AND COMPUTER ENGINEERINGKULLIYYAH OF ENGINEERINGINTERNATIONAL ISLAMIC UNIVERSITY MALAYSIA (IIUM)DECEMBER 2013

ABSTRACT

This report presents the design of band notched antenna with Ultra Wideband applications. There are numerous methods that available in designing and producing the Ultra Wideband antenna with a band notched antenna. Certain applicable methods are presented in this paper. The method that I am using such as modified, L slot patch antenna. This project will examine and summarize the method used in analyzing and designing the Ultra Wideband Antenna. Several principles are used in order to explain the theoretical of Ultra Wideband, Rectangular Patch Antenna and numerical method for analyzing the antenna. The term Ultra shows that the bandwidth that we are targeting to achieve is not just wide, but it must be very - very wide suits to its name Ultra Wideband antenna. For this project, I am targeting the bandwidth of 7.5 GHz which are from 3.1 to 10.6 GHz. The substrate used in the design is FR4 with a dielectric constant 2.2 and the feeding achieved with a microstrip line feed. The design and simulation had been conducted by using CST Microwave Studio Software. All the result from the simulation had been recorded and shown in this report.

Keyword: Ultra Wideband, Dielectric, Patch, Microstrip. Feed line

ACKNOWLEDGEMENTIn The Name of Allah, the Most Gracious and the Most Merciful All Praises be to ALLAH SWT Almighty who helped me to complete this project successfully and gave me the strength and patience throughout this project. This Final Year Project has given me a lot of experience in conducting an important project. I have learn many theory of antenna and also the method of designing Band notched antenna for ultra-wide band applications by microstrip patch antenna. Firstly, i would like to express my gratitude to Allah S.W.T for his blessings and guidance throughout my project. Secondly, I would like to generate my appreciation to my beloved supervisor, PROF. DR. MD RAFIQUL ISLAM for the opportunities to work on this project. His support, advice and guidance are essential for the completion of this project. Without his cooperation and supervision to provide the great ideas, which really helpful, it would be impossible for me to finish this project successfully.I also would like to express my gratitude to Bro. Arnold Chua, by giving me the workshop towards the usage of CST Microwave Studio software, antenna system and design theories. His briefing, gives me a basic understanding of CST software and also I have learned how make a modeling and the simulation of microstrip patch antenna and it provided me more confidence in using the software for simulation. I would also like to thank to Bro Showqat who gives me an idea and also provide me a lot of information towards the design of microstrip patch antenna by using the Computer Simulation Technology (CST).Finally yet important, I want to thanks to all people that support me to make this project possible especially my lovely parent, staff at Department of Electrical and Computer Engineering and numerous friends who always offered their support, encouragement and their great idea. Without their contribution and support, this report would not be as it is today. Thank in advance your kindness.

LIST OF TABLES:Table 1:UWB regulations in in Europe21Table 2: Dimensions of basic rectangle patch antenna61Table 3:Dimension of Basic Patch Antenna64

TABLE CONTENTS: ABSTRACT...............................................i ACKNOWLEDGEMENT.... ii LIST OF TABLES................. ............................. iii LIST OF FIGURES..................................................... vi TABLE OF CONTENTS..................................................... vCHAPTER 17INTRODUCTION71.1Background71.2Problem statement111.3Objectives111.4Methodology111.5Report Organization13CHAPTER 214LITERATURE REVIEW142.3Ultra Wide Band antenna162.4UWB applications242.5Band Notched Antenna252.6Microstrip Patch Antennas282.7Single Patch antenna372.8Previous Work37Chapter 345Design of Ultra Wide Band Antenna with band notched453.1Introduction453.2Antenna parameters463.2.1Return loss463.2.2Frequency Band width463.3Parameters Considerations473.2.1Substrate selection473.2.2Patch Width and Length483.2.2.1Determine the Width, W:493.2.2.2Determine the Length, L:493.2.3Radiation Efficiency493.2.4Feed point location503.2.5 Input Impedance51CHAPTER 4524.SIMULATION AND ANALYSIS524.1 MATLAB Calculation534.2Design of Microstrip Patch Antenna Using CST Simulation54CHAPTER 565CONCLUSION65REFERENCES:-66APPENDIX A68

LIST OF FIGURES: Figure 1: Ultra wideband communications spread transmitting energy across a wide spectrum of frequency.18Figure 2: UWB spectral mask as defined by FCC21Figure 3:The European spectrum mask22Figure 4: Comparison of the FCC indoor UWB mask with the European one23Figure 5: Sample of U Slot technique26Figure 6: Geometry and configuration of the proposed antenna: (a) top layer view, (b) fabricated antenna top layer view, (c) bottom layer view, (d) fabricated antenna bottom layer view.27Figure 7: Geometry of the rectangular patch antenna28Figure 8: (a) and (b) show the geometry of Microstrip (patch)29Figure 9: A Typical Microstrip Antenna30Figure 10: micro strip patch antenna gain32Figure 11:Microstrip Patch Antenna33Figure 12:(a) Top (b) side views of a Rectangular Microstrip Antenna (c) coordinate system.35Figure 13: Coaxial Feed36Figure 14: Microstrip Feed37Figure 15:Geometry of the rectangular patch antenna38Figure 16: Simulated return loss in dB showing that the best performance is obtained for the feedline position L=3.325 from the substrate edge.38Figure 17:Simulated return loss in dB showing that the best performance is obtained for the partial ground width G=7.4mm and G=7.6 mm39Figure 18: Simulated return loss in dB for different feedline width for G=7.6mm and L=3.325mm.40Figure 19: Simulated return loss and VSWR for the antenna with G=7.6mm, L=3.325mm and W=1.8mm.40Figure 20: Simulated return loss of the antenna with slot for varying length ll by maintaining length lw= 11.4mm42Figure 21: Simulated return loss of the antenna with slot for varying length lw by maintaining length ll= 6.6mm.42Figure 22: Simulated return loss of the antenna with slot for varying slot width by maintaining length ll= 6.6mm and lw=11.4mm.42Figure 23: Simulated return loss of the antenna with and without slot after optimization.43Figure 24: Simulated VSWR for antenna with and without slot.43Figure 25: Output of the MATLAB code shows dimension of microstrip parameter.53Figure 26:Dimension of the basic Rectangular Patch Antenna61Figure 27: Radiation pattern of simple Rectangular Patch Antenna for Frequency 7 GHz62Figure 28: 3-D Radiation pattern of the simulated result64Figure 29: electric field (E) of the patch antenna64Figure 30: Magnetic Field of The rectangular microstrip patch antenna65

CHAPTER 1 INTRODUCTION1.1 Background Artificial satellite signaling or in simple definition, antenna also called an aerial, an antenna is a conductor that can transmit, send and receive signaling such as microwave and radio. Ahigh-gain antennaincreases signal strength, where a low-gain antenna receives or transmits over a wide angle. Antenna becomes a part of electrical devices in wireless communication system after late 1888; Heinrich Hertz (18571894) were first demonstrated the existence of radio waves [1]. With the ever-increasing need for mobile communication and the emergence of many systems, it is important to design broadband antennas to cover a wide frequency range. The solution for this is the UWB technology which opens new door for wireless communication system, since the current wireless system increasing exponentially. Back from spark-gap impulse to pulse radio, UWB system plays a dominant role in communication system as the antenna is one of the wireless communications components [1]. Demand for wireless communicating services stimulates the need for antennas capable of operating at a wide frequency ambit the increasing. Since the federal communications commission (FCC) released the commercial apply of UWB radio system many investigators have been paying much attending to high speed indoor data communicating application. Antennas are the particularly challenging aspect of UWB engineering. Various wide band antennas have been studied, to live up to such a requirement. Among the many possible alternatives, planar monopole antennas are good candidates owing to their simple structures, low cost and comfort of construction while featuring wide electric resistance bandwidth, pure vertical polarization and horizontal Omani-directional radiation pattern. The increasing demand for wireless communication services stimulates the need for antennas capable of operating at a wide frequency range. Since the Federal Communications Commission (FCC) released the commercial use of UWB radio system many researchers have been paying much attention to high-speed indoor data-communication application. Antennas are the particularly challenging aspect of UWB technology. To satisfy such a requirement, various wideband antennas have been studied. Among the many possible alternatives, planar monopole antennas are good candidates owing to their simple structures, low cost and ease of construction while featuring wide impedance bandwidth, pure vertical polarization and horizontal omni- directional radiation pattern. However, the UWB communication systems use the 3.110.6 GHz frequency band, which includes the IEEE802.11a frequency band (5.155.825 GHz). Therefore, UWB communication systems may generate interference with IEEE802.11a. The UWB antenna must have the band-notched characteristic at 5.15.825 GHz in order to prevent the signal of the IEEE802.11a frequency band. Recently, various band notched UWB antennas have been developed for UWB communications. Such as the circular disc monopole antenna inserted by an arched slot, the square metal- plate monopole antenna with bevels embedded by an inverted U-shaped slot, and so on.[2] Due to the undesired narrow band signals, such as the signal from the wireless local-area network (WLAN) (5.15-5.35 GHz, 5.725-5.825 GHz), that may interfere with the UWB systems; narrow band interference mitigation must be considered in UWB systems design. Antennas with band notched functions are widely used to overcome the narrow-band interference problem. The most popular strategy to provide this feature is etching a slot on the patch or ground plane or attaching a parasitic strip to the patch or ground plane .Complementary split ring resonator (CSRR) is also used to generate band-notched function effectively Multiple notched bands can be acquired by using band notched filter based on stepped impedance resonator (SIR) There are even configurable UWB antennas with band notches which can be actively switched on or off by using a MEMS or a PIN diode, or tuned by means of a varactor Furthermore, both switchable and tunable characteristics can be achieved in the same UWB antenna by using a PIN and a varactor together However, most of these antennas have only one notch band around WLAN band. Moreover, some antennas occupy the entire 5-6 GHz frequency band which is much wider than needed (200MHz for the lower WLAN band, 100MHz for the upper WLAN band). Therefore, the useful spectrums are wasted and a large waveform distortion may be induced. Other antennas reject only one of the lower and upper WLAN bands. [3] UWB technology with an extremely wide frequency range has been proposed for imaging radar, communications, and localized applications. Since the release by the Federal Communications Commission (FCC) of a bandwidth of 7.5GHz (from 3.1GHz to 10.6GHz) for ultra wideband (UWB) wireless communications [4], UWB is rapidly advancing as a high data rate wireless communication technology. A suitable UWB antenna should be capable of operating over an ultra wide bandwidth as allocated by the FCC. At the same time, satisfactory radiation properties over the entire frequency range are also necessary. Since then, the design of broadband antennas has become an attractive and challenging area in the research of the system design [4]. Antenna designers and engineers have solved the UWB antenna problem in many ways, yielding compact antennas well suited for a variety of applications. They were plenty type of antenna that can be used in achieving the UWB, however in this project we are more focusing in broad banding the antenna using microstrip patch antenna. The design of an efficient wide band small size antenna, for recent wireless applications, is a major challenge. Microstrip patch antennas have found extensive application in wireless communication system owing to their advantages such as low-profile, conformability, low-cost fabrication and ease of integration with feed networks [5]. However, conventional microstrip patch antenna suffers from very narrow bandwidth, typically about 5% bandwidth with respect to the center frequency. This poses a design challenge for the microstrip antenna designer to meet the broadband techniques [6]. Printed microstrip slot antennas are widely used in a variety of communication systems because they can provide many advantages, such as low profile, light weight, easy integration with monolithic microwave integrated circuits, low cost, easy fabrication, and stable radiation patterns [7]. Small bandwidth is the most serious disadvantage of printed microstrip antennas. In order to enhance the bandwidth of a patch antenna, several approaches have been proposed, such as using an impedance matching network , thick substrates with low dielectrics constant and multiple resonators, parasitic patches stacked on the top of the main patch or close to the main patch in the same plane, reactive loading using a U-shaped slot, lossy materials, a capacitive probe-fed structure, L-probe feeding , a combined use of both U-slot loaded patch and L-probe feeding , and a three-dimensional transition microstrip feed line. In most cases, a thick foam substrate is required. A few results for a rectangular patch antenna with an H-shaped slot in the ground plane are given in. Antennas with various shapes of microstrip feed line and rectangular wide slot have been introduced for large impedance bandwidths in their impedance bandwidths have been broadened rapidly from 58% to over than 100% [7]. In addition, applications of the printed microstrip antennas in present day communication systems usually require smaller antenna size in order to meet the miniaturization requirements of radio-frequency (RF) units. Many efforts have also been made for this purpose, for example, adopting short-circuit pin, high dielectric constant substrate, cover layers, and slots loaded on the patch [7]. With the development of communication and integration circuit technologies, size reduction and bandwidth enhancement are becoming important design considerations for practical applications of microstrip antennas. For example, handset internal antennas and RF front-end antennas integration and package at microwave and millimeter-wave bands . Little research has been done to enhance the operation bandwidth and reduce the antenna size with a thin substrate less than 1% of the working wavelength [7]. The objective of this project is to develop a microstrip patch antennas for UWB with band rejection capability. In order to design band-notched antenna with UWB, there are several parameter need to be taken for consideration. The parameters are such as dielectric constant r, length, L and width, W of the patch antenna, the ground size, feeding technique and so on. Therefore, a proper technique is required for designing a band-notched antenna that can produce ultra wideband. In this project, modifying the shape and dimensions of conventional microstrip antennas will be studied, and I will design a rectangular microstrip antenna for ultra wideband communication system by tuning the shape and dimensions.1.2 Problem statement In todays world, we are facing many problems or challenges related to wireless technology. These problems included lack of Ultra Wideband (UWB) antenna. Basically, this problem affects all wireless communication technologies. Furthermore, I will focus to design a band-notched antenna with Ultra Wideband Application. The rapid development of wireless communication urges the need of ultra wide band (UWB) antennas. Wireless personal area network (WPAN) is one of the most popular applications of modern wireless technology. UWB technology is developed to provide the requirements of the WPAN network using 3.110.6 GHz frequency band. On the other hand, in practical applications, UWB antennas must use notch (filter) to reject any interference with existing wireless networking technologies such as the sub-band 5.15.8 GHz. The objective of this project is to develop planar antennas for UWB with band rejection capability.1.3 ObjectivesThe main objectives of this project are as follows:1. To design microstrip patch antenna for UWB applications which included band rejection capability 2. To perform and analyze the result by simulating using Computer Simulation Software (CST).3. To analyze performance of the designed antennas and fabricate the structure of the antenna.1.4 Methodology

The study of microstrip patch antenna provides some calculations of parameters consideration of antenna design. This report illustrates us the design of band-notched antenna for ultra wide band applications by performing the following steps:-A. The first part of the project is to study the theoretical pattern effect of microstrip patch antenna by: Analyze the effect of the Dielectric Constant, r, height h, length L and width W of the microstrip patch antenna to the bandwidth. Analyze the all related antenna parameters for designing ultra wideband antenna. Analyze the propagation mode of the microstrip patch antenna. Analyze the effect of the ground plane to bandwidth.

B. The second part was to create a Matlab code that will calculate the dimension of the rectangular patch antenna.

C. The next part which is the simulation part was performed by using computer simulation technology Microwave Studio (CSTMWS) software. CST Microwave Studio (CSTMWS) allows users to implement 1D, 2&D and 3&D pattern analysis, and evaluate the antenna performance through various data collection such as the return loss (S11), 3D pattern (Gain) and etc. The antenna design can be optimized by using optimization tools included in CST Microwave Studio (CSTMWS).The simulations were done using the following sequence:

The lower frequency band and the upper frequency band is between 3.1GHz to 10.6 GHz. The work starts with designing a rectangular patch antenna which resonates at 6.85 GHz. The simulated resonant frequency may vary from the theoretical calculation approximation. The microstrip patch design has to be optimized to the desired resonant frequency by utilizing optimization features available in the CSTMWS software such as substrate, strip, loft, and start simulation. The next phase is to observe the effect of the truncation of the ground to bandwidth by changing the dimension of the ground. Various data collected from the simulation results such as return loss, gain and patterns are analyzed to find out the optimize design by comparing the theoretic al approximation and the simulation results.D. Finally, the simulation result will be compared with the fabricated result. The fabrication result and the simulation result will be analyzed. 1.5 Report OrganizationIn this project is organized in to five chapters. The chapters are arranged as follows:-Chapter 1: Basically is an introduction on this final year project, ultra wideband antenna, band notched antenna, design methodology and the project objectives.Chapter 2: will covers the literature survey done on different kinds of ultra-wideband antennas, Band notched antennas available, different type of Band-notched antenna and highlights its benefits, applications, standards, regulations, along with the literature about the micro strip patch antenna.Chapter 3: I will discuss the design consideration of microstrip patch antennas, patch antenna, single patch. Factors affecting microstrip design such as microstrip, dielectric, conductor and radiation losses were elaborated in detail. Feeding methods and analysis of the methods are also covered in this chapter.Chapter 4: I will show the simulation results on microstrip patch antenna start with CST-MWS simulation. The partial grounding of the microstrip patch antenna, the slot, and the microstrip patch antenna with out slotChapter 5: Highlights about the conclusion of our project, which focus on techniques that have been used to achieve ultra-wideband and achievement of CST Simulated results and design parameters of band notched antenna.CHAPTER 2LITERATURE REVIEW

2.1 Introduction To start with, microstrip patch antennas were first proposed in the early 1970s and in the meantime a plethora of activity in this area of antenna engineering has occurred, possibly more than in any other field of antenna research and development. Micro strip antennas are planar resonant cavities that leak from their edges and radiate. We can apply printed circuit techniques to etch the antennas on soft substrates to produce low cost and to etch the transmitting aerials on soft substrates to produce low cost we can utilize published circuit techniques. The antennas fabricated on compliant substrates defy tremendous daze and the transmitting antennas fabricated on compliant substrates withstand tremendous environment. Manufacturers for mobile communication base stations often fabricate these antennas directly in sheet metal and mount them on dielectric posts or foam in a variety of ways to eliminate the cost of substrates and etching. This also eliminates the problem of radiation from surface waves excited in a thick dielectric substrate used to increase bandwidth. [8]. In high performance aircraft, spacecraft, and missile applications, where size, weight and cost, performance, ease of installation and aerodynamic profile are constraints, low profile antennas may be required. In addition, presently there are many other government and commercial applications, such as mobile radio and wireless communications that have similar specifications. To meet with such requirements, microstrip antenna can be used. Despite of their convenient in many aspects, they also have major operational disadvantages. Microstrip antenna major operational disadvantages are low efficiency, low power, poor polarization purity, spurious feed radiation and very narrow frequency bandwidth, which is typically only a fraction of a percent or at most a few percent [9]. Maybe in some application, such as in government security system, narrowband width is required. Yet, with the rapid growth of wireless communication, broadband or ultra wide band microstrip antennas are in strong demand to cover various applications with fewer antennas.Ultra wide band is a radio technology for transmitting large amount of data over a wide frequency band with very low power for a short distance. The system covers the frequency range from 3.1GHz to 10.6 GHz, which based on narrow pulse to transmit data of tremendously low power and looks like random noise to mist conventional radio system. In last few years, the development and applications ultra wideband has influences a lot in the communication technology; hence the interest has growth exponentially. In this chapter I will brief about the ultra-wideband antenna, Band-notched antenna and also different types of band-notched antenna with a different shape. [10].2.2 Characteristics of Microstsrip antenna The Microstrip antenna (MSA) has proved to be an excellent radiator for many applications because of its numerous advantages, but it also has some disadvantages.The main advantages of MSAs are listed as follows:1. They are lightweight and have a small volume and low profile planar configuration.2. They can be made conformal to the host surface.3. Their ease of mass production using printed-circuit technology leads to a low fabrication cost.4. They are easier to integrate with other MICs on the same substrate.5. They allow both linear polarization and circular polarization.6. They can be made compact for use in personal mobile communication.7. They allow for dual-band and triple frequency operations.MSAs suffer from some disadvantages as compared to conventional microwave antennas. They are the following:1. Narrow BW.2. Lower gain.3. Low power-handling capacity.2.3 Ultra Wide Band antenna 2.3.1 Brief history of Ultra wide band communication UWB in an unusual type of radio technology, from these days the world of Ultra wide band (UWB) has been changed intensely. Ultra Wide Band is used for radar remote sensing, communications and some part of military applications in the past two decades until now. From the beginning of February 2002, a substantial change occurred when the Federal Communications Commission (FCC) released a declaration that Ultra Wide Band (UWB) can be used for data communications as well us for safety applications and radar (FCC, 2004).Meanwhile, fast advance in UWB communication technology has occurred and hence it offers a promising high data rate wireless communication technology. [11] Ultra-Wideband (UWB) is a communications technology that employs a wide bandwidth (typically defined as greater than 20% of the center frequency or 500MHz). UWB is usually used in short-range wireless applications but can be sent over wires. Ultra-Wideband advantages are that it can carry high data rates with low power and little interference. UWB is the modern version of older "impulse" technologies which are generated by very short pulses (impulse waveforms). They were called "carrier-free" or "baseband" because the energy is so widespread in the frequency domain that there is no discernible carrier frequency. Ultra-wideband(also known asUWB,ultra-wide bandandultra band) is a radio technology pioneered byRobert A. Scholtzand others which may be used at a very low energy level for short-range, high-bandwidth communications using a large portion of the radio spectrum. Most technologies are born and they are either surviving or they die. UWB or ultra wideband seems to do it differently by constantly reincarnating itself and never quite at getting there. Ultra wideband technology is not a new concept although this technology is the revolutionaries of the wireless communication system. The early ultra wideband radio developed by Guglielmo Marconi in the late of 1800s was the pulse-based Spark Gap radio. Transmitting the Morse code through the air waves was employed by this so called pulse-based Spark Gap radio. By 1924, Spark Gap Radios were forbidden in most of the applications due to strong emissions and interference to continuous wave radio system which were developed by early 1900s. [12] The majority of the initial concepts and patents for ultra wideband (UWB) technology are originated in the late 1960's at the Sperry Research Center (Sudbury, MA) and also at the part of the Sperry Rand Corporation, under the direction of Dr. Gerald F. Ross. During that time, this technology was referred by them as baseband, carrier-free or impulse. The term "ultra wideband" was not applied to this technology until approximately 1989. By this time, UWB theory, techniques and many hardware approaches had experienced well over 30 years of extensive development. [12] I will discuss in detail for the advantages of UWB, UWB regulations, UWB applications in a several areas. 2.3.2 Advantage of Ultra Wideband There are many inspiring benefits of UWB that make this technology as a good candidate for wireless broad band compared to the other technologies. The advantages of UWB are explained in following analysis. The reasons of why UWB Antenna becomes a good solution to wireless broadband rather than other technologies are because of it advantageous.

Figure 1: Ultra wideband communications spread transmitting energy across a wide spectrum of frequency.

In the beginning, Ultra wideband can achieve a huge capacity as high as hundreds of Mbps or several Gbps with distance 1 to 10 meters. Such high capacity is due to the characteristics of UWB itself in which it has very wide operating frequency bandwidth. This makes UWB systems perfect candidates for short range, high data rate wireless. Applications such as, Wireless Personal Area Networks (WPANs). Furthermore, based on Shanno- Hartley theorem, channel capacity is in proportional to bandwidth. Consequently, having several gigahertz of bandwidth available for UWB signals, a data rate of gigabits per second (Gbps) can be stated. [11] Moreover, UWB operates at very low power density transmission level. The effect upon any frequency is below the acceptable divide across huge frequency spectrum (cravotta, 2002, Nekoogar, 2005). In short, UWB provides secure and highly reliable communications solutions. The reason is that UWB has very low energy density and its signal is noise like which makes unintended detection quite difficult. Furthermore, the noise- like signal means that the signal has a particular shape compared to the real noise signal in which it has no shape. Because of, it is almost impossible to the red noise to obliterate the pulse because interference would have to spread uniformly across the entire spectrum to obscure the pulse. [11] To sum up, UWB features low cost and low complexity (Aiello, 2006) this is the reason of the fact which UWB is based on impulse radio and a rises from essentially the baseband nature of the signal transmission. On the top of that, UWV does not require components such as mixers, filters, amplifiers, and local oscillators because it does not have modulation and demodulation of complex carrier waveforms. [11] To summarize the above paragraphs, UWB Advantages are as follows: Take advantage of inverse relationship between distance and throughput Huge bandwidth, Very high throughput Low Power Consumption Convenience and flexibility No interference Low cost and Low complexity 2.3.3 UWB regulations The UWB systems operate in a very large bandwidth necessitating it to share the spectrum with other users as well as with the existing communication systems and consequently, interferences may occur. Regulation of UWB radio spectrum is therefore necessary to establish a framework where UWB systems can peacefully co-exist with legacy systems. Radio regulations are rules which address the coordination of spectrum access amongst multiple wireless services and applications. Existing regulations which thus far focus only on narrowband radios will therefore have to accommodate the UWB paradigm. In this Chapter we focus on the regulation of the UWB technology and discuss how this new technology in wireless communications shapes the way of spectrum sharing and consequently impacts the decisions of radio regulation bodies. The objective of this chapter is to give the reader a flavor of the activities of various regulatory bodies to facilitate and streamline UWB spectral access. It should be mentioned at this point that this chapter is by no means a comprehensive and updated document on the UWB regulation efforts, but rather an attempt to indicate the importance of the regulation and standardization of this technology. [13] 2.3.3.1 UWB Regulations in USA UWB regulation sets upper bounds on the power that can be radiated at any particular frequency, both within and outside the core band of 3.110.6 GHz, and is usually specified as a spectral mask. The Federal Communications Commission (FCC) in the US has set out such a mask to regulate UWB communication. The release of the mask was preceded by significant efforts by the industry to promote the UWB technology and convince the FCC to allow license free access to spectrum under FCC part 15 regulations. The FCC Part 15 Rules permit the operation of classes of radio frequency devices without the need for a license or frequency coordination. It also attempts to ensure a low probability of unlicensed devices causing harmful interference to other users of the radio spectrum. On 14 February 2002 the US FCC issued a First Report and Order for UWB technology and authorized the commercial deployment of UWB technology, though subject to technological and operational constraints. This followed extensive consultations that led the FCC to conclude: UWB devices can be permitted to operate on an unlicensed basis without causing harmful interference provided appropriate technical standards and operational restrictions are applied to their use. [13]

The UWB radiation mask defined by FCC has been depicted in Fig. 2, and the Effective Isotropic Radiation Power (EIRP) figures are re-produced in. In the figure and table the limits are for indoor and outdoor handheld systems. The FCC continuously evaluates the UWB technology through tests and measurements and makes necessary amendments. Therefore, the FCC regulations on UWB are expected to evolve with time in the course of developments of future technology.

Figure 2: UWB spectral mask as defined by FCC2.3.3.2 UWB regulations in Europe

Table 1:UWB regulations in in EuropeThe organizations involved in the regulation of UWB in Europe are ETSI (European Technical Standard Institute) and CEPT (European Conference of Postal and Telecommunications Administration). These institutions conduct UWB compatibility and spectrum sharing studies and devise regulatory mechanisms. In 2003 the European Union gave a mandate to the ETSI to establish a set of harmonized standards covering UWB applications. Subsequently in 2004 and following the completion of spectrum compatibility studies by CEPT, ETSI established a task group ERM TG31A to develop a set of harmonized standards for short range devices using UWB technology. The new regulations lay down that UWB equipment should be used predominantly indoors and thus avoid interference. Further, it also imposes a few additional restrictions on device capabilities. For example, it rules that UWB equipments must cease transmission within 10 s unless they receive acknowledgement from an associated transceiver that its transmission is being received. Further, the outdoor use of UWB technology should not include a fixed outdoor location or connected to a fixed outdoor antenna or in vehicles. The technical requirement for the devices using UWB technology in bands below 10.6 GHz permitted under ECC decision is depicted in Fig. 10.2 and Table 10.2. The limits are for indoor UWB communication. Even while recognizing issues of scalability and conformance to global standards for UWB applications, the regulatory bodies in Europe are more cautious than that of the USA. In order to compare the ECC and FCC limits, both masks are illustrated in Fig. 10.3. From this figure it is seen that the European approach to UWB emission is more restrictive than FCC, and only in the band 68.5 GHz does it have the same emission level as the FCC.

Figure 3:The European spectrum mask2.3.3.3 UWB regulations in Japan

Figure 4: Comparison of the FCC indoor UWB mask with the European one The Japanese UWB radiation mask for indoor devices has two bands; from 3.4 to 4.8 GHz and from 7.25 to 10.25 GHz. For the 3.44.8 GHz band, it is required to use a technology to reduce interference with other radio services. This interference mitigation is called Detect And Avoidance (DAA) to ascertain the coexistence with incumbent systems and new services such as 4G systems. However, temporary measures are taken until end of 2008 to permit the use of 4.24.8 GHz band without an interference reduction technology. It should be noted that no DAA is required for the band 7.2510.25 GHz. [13]

2.3.3.4 Short summery based on UWB regulations The regulations, established as mask, sets out upper limits on the amount of power that can be radiated at any particular frequency, both within and outside the core band of 3.110.6 GHz. The wireless networks of different countries operate at different frequencies and therefore the UWB regulation standards are formulated based on local needs. Therefore, devising a generic regulatory standard that caters to all markets across the globe will be one of the goals of the future.[13] 2.4 UWB applications First of all, UWB can provide high data rate transmission with low power consumption at very limited range. This capability leads to the application which is well suited for WPAN. In addition, the peripheral connectivity through cables connections to applications such as input output (I/O) devices, storage and wireless USB will improve the ease and value of using personal computers (PCs) and Laptops. Secondly, many types of sensors can also be provided by UWB technology and thus offer and opportunity for it to flourish (Siwiak and Mckeown, 2004: Mehter and Elzarki, 2004). Sensor network comprised of a large number of nodes within a geographical area. These nodes may be static or mobile. The nodes are static when applied for security home, tracking and monitoring (Yang and Gannakis, 2004). Thirdly, UWB can be used for positioning and tracking applications. UWB can provide and excellent solution for indoor location with better accuracy than a GPS because of its high data rate characteristic in short range. Lastly, another unique property of UWB is that it can be applied to radar and imaging applications. It has been used in military applications to locate un seen objects behind the walls and around corners in the battle field. (Levitas and Matuzas, 2006), Besides it has also a commercial usage such as medical diagnostics where X-ray systems may be less desirable. [11]To summarize the above paragraphs, UWB applications are classified Eight major categories. Communications and sensors Position location and tracking Radar imaging applications Military applications for un seen objects behind the world and commercials Wireless USB Toys and Games Consumer Electronics Handset 2.5 Band Notched Antenna 2.5.1 Different Geometry of Band Notched antenna with UWB An alternate way to reduce the resonance frequency of the microstrip patch antenna is to increase the path length of the surface current by cutting slots in the radiating patch. There are plenty of types that can be used such as: U Shaped Patch W Shaped Patch Turning fork type UWB patch All these type of slot are widely used in order to achieve the UWB characteristics. Here, all these type will be discussed more briefly to have more understanding of these techniques.

2.5.1.1 U slot shape It is observed in previous section that by cutting a slot inside or along the periphery of the rectangular microstrip patch antenna, various compact configurations are realized with a reduced bandwidth. If the resonance frequencies of the slot and the patch are close to each other, then broad bandwidth could be obtained. However, care must be taken so that the polarization of the radiated field of the slot and the patch are similar, so that the pattern remains stable over the VSWR bandwidth. A very promising configuration that yields broad bandwidth is a rectangular microstrip patch antenna with a U-shaped slot [78]. A resonant U-slot is cut symmetrically around the center of the patch. A slot is cut inside the patch, the resonance frequency of the patch changes slightly in comparison with the resonance frequency of the slot. On the other hand, for the rectangular microstrip patch antenna without a U slot, there would be large inductive reactance in the input impedance of the patch, because the substrate is electrically thick and even if the feed point is shifted to the edge of the patch, it is not possible to achieve impedance matching. So, a U-slot adds a capacitive component in the input impedance that compensates for the inductive component of the coaxial probe.

Figure 5: Sample of U Slot technique

2.5.1.2 W slot Figure 1 shows the geometry of the proposed antenna, with a W-shaped slot on the radiating patch. The patch has the form of a rectangle with a three steps at its lower end to improve the matching of the antenna over the operating bandwidth. A partial ground plane with a slit is used on the other side of the substrate. The total size of the antenna is 30mm 35mm with metal thickness of 0.07 mm. The used substrate is FR4 which has dielectric constant, r = 4.4 and its thickness, h = 1.57 mm. [14]

Figure 6: Geometry and configuration of the proposed antenna: (a) top layer view, (b) fabricated antenna top layer view, (c) bottom layer view, (d) fabricated antenna bottom layer view.2.5.1.3 Tuning Fork type UWB PatchThe structure of the antenna is shown in Fig. 1. A rectangular patch of dimension 12.45 mm16mm is on one side of an FR4 substrate of thickness 0.8 mm and relative permittivity 4.4 with the partial ground plane located on the other side. The dimension for the substrate is 32 mm28mm.The antenna plate is fed by a microstrip of 50 feedline of width W and placed L distance from one edge of the substrate. The width of the partial ground is G. The parameters W, L and G are optimized to operate the antenna within UWB range. The cut part is shown within the rectangular patch. The width of the cut part is 8mm and the length of the cut part is Lc, when Lc=14 mm, the rectangular patch becomes tuning fork type patch. [15 ]

Figure 7: Geometry of the rectangular patch antenna

2.6 Microstrip Patch Antennas

Microstrip antenna had received attention starting 1970s, although the idea of a microstrip antenna can be traced to 1953 and patent in 1955.A large number of patch microstrip antennas have been studied and used up to date. The rectangular and circular patches are the basic and most commonly used microstrip antennas. These patches can be used for the simplest and the most demanding applications. For instance, characteristics such as dual and circular polarizations, dual frequency operations, frequency agility, broad bandwidth, feed line flexibility, Omni-directional pattern and so on are easily to achieve.

(a)

(b)Figure 8: (a) and (b) show the geometry of Microstrip (patch)As shown in figure 8, a micorstrip antenna in its simplest configuration consists of a radiating patch on one side of a dielectric material (r < 10), which has a ground plane on the other side. The patch conductors, normally of copper or gold, can assume virtually any shape, but regular shapes are generally used to simplify analysis and performance prediction. Ideally, the dielectric substrate should be low (r < 2.5), to enhance the fringe field that account for radiation [9]. However, other performance requirements may need to use dielectric constant whose dielectric constant greater than the above mentioned value.

Figure 9: A Typical Microstrip AntennaMicrostrip antennas are characterized by a larger number of physical parameters than are conventional microwave antennas. All microstrip antennas can be divided into four categories: microstrip patch antennas, microstrip dipoles, printed slot antennas, and microstrip traveling wave antennas. They can be designed to have many dimensions and shapes. A microstrip patch antenna consists of a conducting patch of any planar or non-planar geometry on one side of a dielectric substrate with a ground plane on the other side. The typically a patch antenna has a gain between 5 and 6 dB. However, related to our study where achieving the UWB bandwidth is the main target, the rectangular microstrip antenna will be studied carefully and will be used to accomplish the required design. [9]2.6.1 Characteristics and specifications of Microstrip Patch AntennaA microstrip or patch antenna is a low profile antenna that has a number of advantages over another. This topic will introduce some of the basic concepts that we have to know about the microstrip patch antenna. However, the main focus will be on explaining the characteristics and specifications of microstrip patch antenna in order for us to be familiarize with this antenna that we are going to design. Firstly, we are going to discuss on the fundamental specifications of microstrip patch antenna.2.6.2 Fundamental Specifications of Patch Antennas

Radiation Pattern The patchs radiation at the fringing fields will results in a certain far field radiation pattern. This far field radiation pattern shows that the antenna radiates more power in a certain direction than another direction. So, this antenna is said to have a certain directivity which commonly expressed in dB. The rectangular patch that excited in its fundamental mode has maximum directivity in the direction perpendicular with the patch (broadside). The directivity decreases as it moving away from broadside towards the lower elevations. 3 dB beam width or angular width is twice the angle respect to the angle of the maximum directivity. Hence, this directivity has rolled off 3 dB with respect to the maximum directivity. [17]Antenna GainAntenna gain is the antenna directivity times a factor representing the radiation efficiency. Efficiency also is defined as the ratio of radiated power to the input power. Input Power transformed into radiated power and surface wave power while a small portion is dissipated due to conductor and dielectric losses of the materials used. Furthermore, antenna gain also can be specified using the total efficiency instead of the radiation efficiency only. So, total efficiency is a combination of the radiation efficiency with efficiency linked to the impedance matching of the antenna. [18]

Figure 10: micro strip patch antenna gainPolarizationThe plane where the electric field varies is also known as polarization plane. It is important to know the polarization plane of the patch antenna in order to determine the application of it.BandwidthThe bandwidth of the antenna can cover is also another important parameter of the antenna. Directivity and efficiency are always combined as gain bandwidth.2.6.3 Characteristics of Microstrip Patch Antenna

Figure 11:Microstrip Patch AntennaMicrostrip antenna as shown in Figure 2.4 consists of a very thin metallic strip placed a small fraction of a wavelength above a ground plane. The microstrip patch is design so its pattern maximum is normal to the patch. This is accomplished by properly choosing the mode of excitation beneath the patch. For rectangular patch, the length L of the element is usually 0 /3< L L. Moreover, we can get an expression for xf which is [19]: . (3.9)Where . (3.10)3.2.5 Input ImpedanceInput impedance of antenna at its terminal is defined to be the ratio of voltage to current at a pair of terminals or the ratio of the appropriate components of the electric to magnetic field at the point. Input impedance are the important parameter that have to be considered in designing the antenna since it is important to match the antenna element to the input transmission line. Approximate expression also will be discussed in order to describe the variation of the resonant input resistance as a function of the inset feed position. Generally, the input impedance is complex and it also includes both a resonant and a non resonant part which is usually reactive. Real and imaginary parts of the impedance are both vary as a function of frequency. Both the resistance and reactance ideally exhibit symmetry about the resonant frequency and the reactance at resonance is equal to the average of sum of its maximum value which is positive and its minimum value which is negative. For very thin substrate, typically the feed reactance is very small compared to the resonant resistance. However for thick elements, the reactance may be significant and needs to be taken into account during impedance matching also for determining the resonant frequency of a loaded element. After concerning the impedance, the magnetic wall will be taken into account by introducing multiple images with current flow in the same direction as the actual feed. The largest reactance is when the feed is at or near a corner while the smallest is when the feed is far removed from an edge or corner. A formula that has been suggested to approximate the feed reactance is.. (3.11)Where d is diameter of the feed probe. [6]CHAPTER 44. SIMULATION AND ANALYSIS In this chapter I will provide a simulation by using Computer Simulation Technology Software and MATLAB Software. First of all, I used MATLAB software in order to calculate the parameters such us, Width, Height, and Length and feed line. Based on the design by the designer from entire nation, I can conclude that using this three methods is most preferable method for m in term of ease of fabricate and most importantly it will give me the desired output which is Ultra Wide Band frequency. The methods are: Partial grounding. L slotIn order to determine the best design, there are several parameters that will be taken into account such as radiation pattern, return loss S11, and bandwidth. The screen shot of the simulation and results (return loss, S11) will be included in this chapter. 4.1 MATLAB Calculation To start with the simulation, first of all we need to have the dimension of the rectangular microstrip patch antenna. In order to calculate the dimension, we have to setup the calculation in the MATLAB software. The MATLAB code are created base on the equation of the patch that have been explained in chapter 3. By using MATLAB software, we have got the dimension needed for our design and simulation. The dimension needed are such as physical width of patch, W, effective length of patch, L eff, and physical length of patch, L. The constant parameter that we need to have such value that have been mention before are resonant frequency, f0, dielectric constant of substrate (r), height of the substrate (h) and the input impedance, Z0. Figure 4.1 below is the screenshot of the MATLAB windows that shows all the dimension result.Figure 25: Output of the MATLAB code shows dimension of microstrip parameter.

4.2 Design of Microstrip Patch Antenna Using CST Simulation

Before achieving the objective of the project which is to get the UWB frequency, firstly it is necessary for us to begin with the simple rectangular patch antenna. Later we will start to analyze the effect of the ground dimension and the further studies of the effect of the stairs and also slotted ground. Therefore, it is important for us to start the simulation for the simple rectangular patch antenna and try to get the optimum performance. The construction and simulation of the antenna is done by following procedure. Explanation of each steps are as follow:Step 1: Template is selected.

Step 2: Working Planes Properties is set and the properties

Step 3: The Substrate Brick is drew.

Step 5: Rectangular Patch Antenna is modeled

Step 6: The width of feed is calculated.Step 7: The feed is modeled; the feed is designed and inserted into the patch.

Step 4: The Ground Plane is modeled.Step 8: The Waveguide Port is defined; the excitation port is added to the patch antenna.

Step 9: The Frequency Range is defined.

Step 10: The Boundary Conditions is defined.Step 11: Far field Monitor is defined; we are interested in far field gain and E-field pattern.

Step 12: Simulating: S-parameters and the far field are calculated using the transient solvers.Table 4.1 summarizes the result of MATLAB calculation for Microstrip Antennas dimension:

ParametersValue Description

Type of the antenna FR4.

Lower Frequency 3.1 GHz

Upper Frequency 10.6

Resonant Frequency 6.85 GHz

Dielectric constant 2.2

Bandwidth7.5 GHz

W32 mm Width of the substrate

L 28.1 mm Length of the substrat

t 0.8 mm Thickness of the substrate

PW16 mmPhysical width of the patch

PL14.05 mmPhysical length of the patch

T0.8 mmThickness of the patch

Wf h1.8 mmWidth of the microstrip feed

Lf8 mmLength of microstrip feed

Wsh 11.4 mmThe width of the slot in horizontal

Lsh-0.5 mm The length of the slot in horizontal

T0.07 mm The thickness of the cutting plane

Wsv 0.5 mmThe width of the slot in vertical

Lsv-6.6 mm The length of the slot in vertical

T 0.07 mmThe thickness of the slot

Table 2: Dimensions of basic rectangle patch antenna

Figure 26:Dimension of the basic Rectangular Patch AntennaAfter getting the dimension of the simple rectangular patch antenna, we try simulating it by using the CST Microwave software and get the following result. Note that for this result we are achieving it without modifying any of the antenna structure. We are using the fully ground structure and the patch in the standard dimension. Figure 4.3: Return Loss, S11 of simple Rectangular Patch Antenna

Figure 27: Radiation pattern of simple Rectangular Patch Antenna for Frequency 7 GHzFigure 27 shows the result of the simulation. It shows the return loss, S11 of the antenna. However, theoretically, the minimum value of the return loss, S11 should be at the resonant frequency of the antenna for around 7 GHz. Form Figure 27 we also can see that the impedance matching was satisfied since the return loss, S11 which represent the ratio of the reflected wave and the incident wave is very small which equal to -29.9846 dB. However, it is assumed to be a good matching as long as the values obtain are below -10 dB. There are another problem occurred with result obtained which the matching does not occurred at the resonant frequency that have been set before which is 7 GHz. Instead, it is resonating at the frequency of 7.886 GHz. Thus, optimizations are required in order for us to achieve the desired resonant frequency with acceptable return loss, S11. Following subtopic will discuss and shows the simulated result of the optimization. We will start the optimization process with modifying the dimension of the ground. Parameter UsedValue

Type of AntennaFR4

Resonant Frequency6.85 GHz

Dielectric Constant2.2

Height of Substrate, h0.8

Length of the whole geometry, L32 mm

Width of the whole geometry, W28.1 mm

Physical Width of Patch Antenna, WP16 mm

Effective Length of Patch Antenna14.05 mm

Width of the Feed, WF0.5 mm

Length of the Feed, WP11.4 mm

Table 3:Dimension of Basic Patch Antenna

Figure 28: 3-D Radiation pattern of the simulated result

Figure 29: electric field (E) of the patch antenna

Figure 30: Magnetic Field of The rectangular microstrip patch antenna

CHAPTER 5CONCLUSION In conclusion, theory behind ultra-wide band system as well as the parameter consideration and the techniques apply to increase bandwidth of the micro strip Patch antenna has been studied. The physical parameters such as dimension and location of the substrates, effect of dielectric constant, feed line, ground plane and patch of the antenna were examined in this study. Antenna parameters also had been determined after computer simulation like resonant frequency, input electric resistance, bandwidth, return loss and transmitting aerial parametric quantities also had been determined after computer simulation like resonant frequency, input electric resistance, bandwidth, come back loss and directivity. The design of the ultra-wideband antenna in this project was done by three approaches in symmetrical design. The approaches are included, partial ground, stairs and slotted ground. The configuration has been analyzed by applying CST software. The bandwidth achieved is 7.5 GHertz and the return loss is -45.963 dB which is below than 10 dB that is acceptable. But, this is only my preliminary consequence and I will do further optimization with other different design in FYP 2.REFERENCES:-[1] DESIGN AND CONSTRUCTION OF MICROSTRIP UWB ANTENNA WITH TIME DOMAIN ANALYSIS,K.-S. Lim, M. Nagalingam, andC.-P. Tan, Hertz, H., Electrical Waves, London, Macmillan and Co. 1893.[2] Designing an UWB patch antenna with band notched by using L-shaped slot and unsymmetrical feed line, A.H.M. Zahirul Alam, Md. Rafiqul Islam, Sheroz Khan,Faculty of Engineering, International Islamic University Malaysia (IIUM) Faculty of Engineering, IIUM, P.O. Box 10, 50728 Kuala Lumpur, Malaysia.[3] Progress in Electromagnetics Research B, Vol. 39, 393-409, 2012[4] FCC, First Report and Order 02-48. February 2002.[5] He W., Jin R., Geng J. (2008) E-Shape patch with wideband and circular polarization for millimeter-wave communication. IEEE Transactions on Antennas and Propagation 56(3), 893-895.[6] Lau K.L., Luk K.M., Lee K.L. (2006) Design of a circularly-polarized vertical patch antenna. IEEE Transactions on Antennas and Propagation. 54(4), 1332- 1335[7] IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION, VOL. 56, NO. 10, OCTOBER 2008[8] Thomas .A. Milligan. Modern Antenna Design, 2nd Edition, A JOHN WILEY & SONS, INC., PUBLICATION[9] Balanis, C. A. (2005). ANTENNA THEORY : ANALYSIS AND DESIGN. Hoboken, New Jersey: John Wiley & Sons, Inc.

[10] C.Vishnu Vardhana Reddy Rahul Rana. Design of Linearly Polarized Rectangular Microstrip Patch Antenna Using Ie3d/Pso Department of Electronics and Communication Engineering National Institute of Technology Rourkela[11] Nuurul Hudaa Bint Mohd Sobli. DESIGN OF A COMPACT BAND NOTCHED ANTENNA FOR ULTRA WIDEBAND COMMUNICATION. KULLIYAH OF ENGINEERING IIUM, OCTOBER 2009. [12] J.Fontana, D. (N.D.). A Brief History Of UWB Communication . Multi Spectrum Solution ,Inc .[13] H. Nikookar, R. Prasad, Introduction to Ultra Wideband for Wireless Communications, Signals and Communication Technology, DOI 10.1007/978-1-4020-6633-7_10, _ Springer ScienceBusiness Media B.V. 2009 [ 14] DESIGN OF A COMPACT PRINTED BAND-NOTCHED ANTENNA FOR ULTRAWIDEBAND COMMUNICATIONS, N. H. M. Sobli and H. E. Abd-El-Raouf, Progress In Electromagnetics Research M, Vol. 3, 57 78, 2008

[ 15] Design of a Tuning Fork type UWB Patch Antenna A. H. M. Zahirul Alam, Rafiqul Islam, and Sheroz Khan, International Journal of Computer Science and Engineering Volume 1 Number 4.[16] DESIGNING AN UWB PATCH ANTENNA WITH BAND NOTCHED BY USING L-SHAPED SLOT AND UNSYMMETRICAL FEEDLINE,A.H.M. Zahirul Alam, Md. Rafiqul Islam, Sheroz Khan Faculty of Engineering, International Islamic University Malaysia (IIUM) Faculty of Engineering, IIUM, P.O. Box 10, 50728 Kuala Lumpur, Malaysia.[17] D. Orban and G.J.K. Moernaut. The Basics of Patch Antennas, Orban Microwave Products[18] G.A. Deschamps, (1953). Microstrip Microwave Antennas, Presented at the Third USAF Symposium on Antennas,.[19] Pozar, D. (1992). "Microstrip Antenna" . IEEE ,vol 80 , 79-91.

[20] Ramesh Grag , Pakash Bhartia , Indera Bahl Apisak Ittipiboon . (2001). "MicrostripAntenna Handbook Design ". London : Artech House .

[21] Indra Surjati, Y. K. (2010). Microstrip Patch Antenna Fed by Inset Microstrip Line For Radio Frequency Identification (RFID). Asia-Pacific International Symposium onElectromagnetic Compatibility. Beijing, China.[22] Girish Kumar, K. P. (2003). Broadband Microstrip Antennas. Artech House.

APPENDIX AATTECHMENT OF MATLAB CODE FOR PATCH ANTENNA CALCULATIONfunction []=MICROSTP;clear all;close all;warning off; % Input Parameters (freq, epsr, height, Yo)freq=[];while isempty(freq), freq=input('INPUT THE RESONANT FREQUENCY (in GHz) = ');end;er=[];while isempty(er), er=input('INPUT THE DIELECTRIC CONSTANT OF THE SUBSTRATE = ');end; h=[];while isempty(h), h=input('INPUT THE HEIGHT OF THE SUBSTRATE (in m) = ');end; Zin=[]; while isempty(Zin), Zin=input(['INPUT THE DESIRED INPUT IMPEDANCE Zin (in ohms) = ']); end% Compute W, ereff, Leff, L (in cm)W=0.3/(2.0*freq)*sqrt(2.0/(er+1.0));ereff=((er+1.0)/2.0)+((er-1)/(2.0*sqrt(1.0+12.0*h/W)));dl=0.412*h*((ereff+0.3)*(W/h+0.264))/((ereff-0.258)*(W/h+0.8));lambda_o=0.3/freq;lambda=0.3/(freq*sqrt(ereff));Leff=0.3/(2.0*freq*sqrt(ereff));L=Leff-2.0*dl;ko=2.0*pi/lambda_o;Emax=sinc(h*ko/2.0/pi); % Input Impedance at Y=0 and Y=Yo[G1,G12]=sintegr(W,L,ko);Rin0=(2.*(G1+G12))^-1; Y=acos(sqrt(Zin/Rin0))*L/pi;disp(strvcat('INPUT PARAMETERS','================'));disp(sprintf('\nRESONANT FREQUENCY (in GHz) = %2.2f',freq));disp(sprintf('DIELECTRIC CONSTANT OF THE SUBSTRATE = %2.2f',er));disp(sprintf('HEIGHT OF THE SUBSTRATE (in cm) = %2.2f',h));disp(sprintf('\nPHYSICAL WIDTH OF PATCH (in m) = %2.2f',W));disp(sprintf('EFFECTIVE LENGH OF PATCH (in m) = %2.2f',Leff));disp(sprintf('PHYSICAL LENGH OF PATCH (in m) = %2.2f',L)); fprintf('FOR DESIRED IMPENDANCE %2.2f ohms, THE FEED POINT POSITION Yo=%2.2f m\n\n',Zin, Y); function [G1,G12]=sintegr(W,L,ko)th=0:1:180; t=th.*pi/180;ARG=cos(t).*(ko*W/2);res1=sum(sinc(ARG./pi).^2.*sin(t).^2.*sin(t).*((pi/180)*(ko*W/2)^2));res12=sum(sinc(ARG./pi).^2.*sin(t).^2.*besselj(0,sin(t).*(ko*L)).*sin(t).*((pi/180)*(ko*W/2)^2));G1=res1./(120*pi^2); G12=res12./(120*pi^2);