ijest11-03-10-197

7/29/2019 IJEST11-03-10-197

1/19

RECTENNAS DESIGN,

DEVELOPMENT AND APPLICATIONS*Rakesh Kumar Yadav,

**Sushrut Das and

*R. L. Yadava,

*Department of Electronics & Communication Engineering, GCET, Gr. Noida, U. P., India

**Department of Electronics Engineering, Indian School of Mines, Dhanbad, Jharkhand, India

[email protected]

ABSTRACT

The present paper describes the development of rectenna in terms of its applications in MicrowavePower Transmission, Harmonic Rejection, CP radiation and ISM band. These rectennas consist of severalantennas such as dipole, antenna arrays, slot meander line and rhombic loop antennas along with the rectifyingdiodes. In some cases more than one rectifying devices have also been used and antenna is found to be act atdual bands. It has also found that rectenna reject the harmonics upto 3 rd order and enhanced the performancecharacteristics. The maximum efficiency about 91% with 1.2 W of input power has been observed if therectenna is used for microwave transmission.

KEYWORDS:

Rectenna, Conversion Efficiency, Band Reject Filter, Voltage Standing Wave Ratio, Industrial-Scientific-Medical Band, Microwave Power Transmission.

I. INTRODUCTIONThe rectenna has been a growing area of research in recent years, as the microwave integrated circuit and

monolithic microwave integrated circuit technologies became more mature allowing for high level integration.The rectenna termed as rectifying antenna, is combination of an antenna and a nonlinear rectifying element

(Schottky diode, IMPATT diodeetc.) where the two elements are integrated into a single circuit. The

schematic of a rectenna system is shown in Fig. 1. Such a system is capable to receive and detect microwavepower and converts the RF power into dc voltage at high frequencies (THz).

Fig.1 Schematic rectenna system.

Since the rectenna is a receiving module collecting power from a radiation field, its sensitivity is defined by

= Division of this value with the effective antenna aperture leads to the normally used quantity for detectors.

= This characterizes the nonlinear element with its matching.

A rectenna is useful as the receiving terminal of a power transmission system where dc power needs to bedelivered to a load, through free space, for which physical transmission lines are not feasible. It is also suitablein applications where dc power needs to be distributed to more numbers of load elements that are spatially

Rakesh Kumar Yadav et al. / International Journal of Engineering Science and Technology (IJEST)

ISSN : 0975-5462 Vol. 3 No. 10 October 2011 7823

7/29/2019 IJEST11-03-10-197

2/19

distributed. Such power distribution is achieved by the dispersive nature of microwave energy in space,eliminating the need for physical interconnects to individual load elements.

The rectenna was invented by Brown and has been used for various applications such as the microwave

power helicopter and the receiving array for Solar Power Satellite [1-5]. The experiment on the microwavepowered aircraft which was conducted in Canada under the project SHARP (Stationary High Altitude Relay

Platform), in which the structure of rectenna was evolved from a bulky bar-type to a planar thin-film type. It wasfound that the weight to power output ratio reduces effectively, and the power conversion efficiency of 85% isobserved at 2.45 GHz [6, 7].

In general it is difficult to predict how the rectenna system is optimized for the maximum conversionefficiency. However, there are several theoretical methods to overcome this problem. These methods can be

divided into two groups; the first one is to directly simulate the rectenna circuit in time domain [8], whereas theother is to find a closed-form equation which can explain the relationship between diode parameters and theconversion efficiency [9-10]. All these studies were done on 2.45GHz because it is not strongly attenuated bythe atmosphere even under a severe weather condition [11]. The frequency 2.45 GHz is suitable for theapplication of power transmission between ground-to-ground, ground-to-space and space-to-ground. However,the operating frequency can be increased to allow power transmission for the space-to-space application, over

much longer distances with the smaller antenna and rectenna. Fig. 2 shows the plot of rectenna conversion

efficiency with the input power.

Fig. 2 General relationship between microwaves to dc power conversion efficiency and input power.

The main objective with the design of rectenna is to obtain high conversion efficiency, and there are twoapproaches to achieve this goal. In first maximum power is collected and delivered to the rectifying diode, while

in the second one harmonics generated by the diode are suppressed, which re-radiate from the antenna as powerlost. In order to increase conversion efficiency by the first method, several broadband antennas, large antennaarrays and circularly polarized antennas have been designed and experimented. The broadband antenna enablesrelatively high RF power to be received from various sources while the antenna array can increase incidentpower delivered to the diode by enlarging antenna aperture and antenna gain. Antenna array is an effectivemeans to increase the receiving power for rectification. However, a trade-off arises between the antenna size and

the radiation gain. The circularly polarized antenna offers power reception with less polarization mismatch.However in second method, the rectenna consist of an LPF between the antenna and the diode, as well as anadditional LPF on the dc output side of the diode. The main reason for the rise in the efficiency was theimprovement in the diode and circuit construction for high input power levels.

Several operating frequencies of the rectenna have been considered and investigated. Components ofmicrowave power transmission have traditionally been focused on 2.45 GHz and recently moving up to 5.8

GHz, which has a smaller antenna aperture area than that of 2.45 GHz. Both frequencies have comparably lowatmospheric loss, cheap components availability, and reported high conversion efficiency. That is, the rectennais capable of very high conversion efficiencies (~90%) in optimal circumstances and hence very suitable forautomotive radar applications. Therefore in present paper authors describe the progressive development ofrectenna, during last two decades, focusing its importance in microwave power transmission, harmonicrejection, CP radiation, dual frequency and high efficiency and ISM band applications.



7/29/2019 IJEST11-03-10-197

3/19

II. MICROWAVE POWER TRANSMISSION

The receiving rectifying antenna (rectenna) is one of the main components of microwave powertransmission systems. In order for such systems to operate cost efficiently in land or spaced-based locations, the

conversion efficiency from microwave to dc of the rectenna must be high. In year 1992, J.O. Mcspadden, T.Yoo and K. Chang designed a 35 GHz rectenna using a microstrip patch antenna and 29% of measuredefficiency was found with 120 mW input power. The measured efficiency versus input power for a 100 load

resistance is shown in Fig.3.

Fig. 3 The power conversion efficiency of the 35 GHz rectenna measured with the waveguide array simulator.

They also designed a frequency selective surface using an equivalent circuit model and tested to pass 2.45GHz with insertion loss of 0.3 dB [12]. It also rejects the second harmonic of 4.9 GHz. The frequency response

of the gridded square FSS array is shown in Fig. 4. The 10 dB of attenuation occurred at 4.9 GHz on a smallrectenna array whereas the conversion efficiency was decreased by less than 1%.

Fig. 4 Calculated and measured frequency response of the gridded square FSS array.

After 6 years, K.M. Strohm, J. Buechler and E. Kasper designed a rectenna on high resistivity siliconsubstrate using SIMMWIC technology [13]. The microstrip rectenna with two Schottky diode and single diodeis shown in Fig 5, where the rectenna are combined with a CMOS preamplifier mounted as a multichip modulenext to the rectenna. They found the amplification of 32 dB while maximum sensitivity of the detector circuit

including pre-amplification is 1600 mV/mW.cm-2

at 94.6 GHz. The frequency response and radiation pattern areplotted in Fig. 6 and Fig. 7, which show a 3 dB BW of 1.6 GHz.



7/29/2019 IJEST11-03-10-197

4/19

Fig. 5 Photo of the microstrip rectenna. (a) Two branches antenna with two Schottky diodes in series (b) Antenna with single diode

Fig. 6 Output voltage of the rectenna/CMOS MCM versus frequency (S = 4.7 W/cm2)

Fig.7 H-plane radiation pattern of the packaged rectenna/CMOS module.

In year 2000, L.W. Epp et al. [14] proposed a compact rectenna capable of producing a 50 V output suitablefor driving mechanical actuators. They describe the circuit that allows the output of multiple rectenna elements

to be combined in order to step up the output voltage. For each of the two orthogonal polarizations (dual linearand circular) independent circuit is used. By suitable choice, the output voltage is twice over that of the single

polarization case. These are used in the next generation space telescope to eliminate wiring between actuatorsand provide true mechanical isolation. By proper diode placement and adding resistance dc isolation pads, theyfound that a series combination of 9 patch element would combine the output of 18 diodes for dual polarization.For actuator application this allow for large output voltage for low incident power density. Fig.8 shows that byincreasing load resistance the required 50V output can be obtained for a low incident power density of 6.3mW/cm2.



7/29/2019 IJEST11-03-10-197

5/19

Fig. 8 Output voltage for a rectenna panel with load chosen to maximize activator voltage while minimizing the transmit power needed.

However, J.A.G. Akkermans et al. proposed low cost rectenna for low power application, shown in Fig.9.The main design parameters of the rectenna considered; are dimensions and conversion efficiency which is

defined as

= (1)The main component of the rectifying circuit is Schottky diode, which has voltage current characteristics

defined by;

= 1 (2)And during stationary operation the current through the nonlinear diode is

= cosnt sinnt (3)The coefficient and can be found out by minimizing the square of the error between and

over one period of time T.

= = 1 0 (4)The coefficient can be found via a multi-dimensions minimization method. This allow for a fast design of

rectenna system. To acquire small area a layered design is proposed. They found a 40% of conversion efficiency[15].

Fig. 9 Schematic layout of the rectenna



7/29/2019 IJEST11-03-10-197

6/19

B. Essakhi, L. Pichon and G. Akoun [16] proposed a computationally efficient model of a broadbandmicrowave rectenna. The rectenna with RF to dc circuit is shown in Fig. 10. They calculated the impedance ofantenna over a wide frequency band by the 3D FEM and Pade approximations methods. Then an equivalentcircuit was designed. The resulting equivalent circuit of antenna together with lumped component of rectenna

(diodes and loads) has been incorporated into PSPICE. Such an approach provides a significant improvement atthe design stage of a rectenna in the framework of microwave power transfer.

Fig. 10 Rectenna with RF-to-dc circuit

However, N. Shinohara and H. Matsumoto proposed a 3.2 m x 3.6 m rectenna array consisting of 256 sub-arrays where each of the sub-arrays has 9 rectenna elements connected in parallel [17].They tested two differentarrays, one is an array placing the high efficiency sub array in the central area of the array and other is nonarranged and found that arranged array provides 46% higher dc maximum output. They checked dependency of

rectenna array characteristics on the electrical connection with 5 different methods as shown in Table I andfound that the differences of the output dc power is within 5%. The findings are useful for construction of large

rectenna array.

However in 2004, J. A. Hagerty et al. [18] designed a 64 element dual CP spiral rectenna array over a

frequency range of 2-18 GHz with single tone and multi tone incident waves. The integration of antenna andrectifier, using full wave electromagnetic field analysis and harmonic balance nonlinear circuit analysis gives a

compact design because it eliminates matching and filtering circuit. Fig. 11 shows an equiangular spiral antennawith a packaged Schottky diode. The ambient RF power levels vary by several orders of magnitude, implying avarying dc load as reflected in the I-V characteristics of single rectenna element as shown in Fig. 12. Theapplications of proposed rectenna are wireless powering of industrial sensors and recycling of ambient RF

energy.

Fig. 11 Layout of the spiral antenna element with a packaged Schottky diode connected directly at the feed



7/29/2019 IJEST11-03-10-197

7/19

Fig. 12 SimulatedIVcurves as a function of load resistance and input RF power to the diode. The peaks in rectified power areindicated by circles with the corresponding optimal load resistance.

III. HARMONIC REJECTION

A rectenna having the property of harmonic rejection eliminates the requirement of LPF between the antennaand diode. In this way, additional insertion loss at the fundamental frequency associated with the LPF in a

conventional system can be eliminated to produce higher efficiency. A.Georgiadis, G. Andia, and A. Colladoproposed a methodology to design a rectenna utilizing reciprocity theory and combining electromagnetic (EM)simulation and harmonic balance (HB). They designed a 2.45 GHz rectenna, based on a square aperture-coupledpatch antenna with dual linear polarization and found that by etching a cross shaped slot on the patch surface,the size of patch is reduced by 32.5% [19]. The circuit is optimized for low input power densities and amaximum efficiency of 38.2% at a load of 6.2 K was achieved for 1.5 uWcm

-2input RF power densities at

2.43 GHz as shown in Fig. 13. The dependency of the efficiency on the load at 2.45 GHz is shown in Fig. 14and gives the optimum load value of 4.5 K.

Fig. 13 RF-to-dc efficiency versus frequency (RL= 6.2 K)

Fig. 14 RF-to-dc efficiency versus load impedance (f = 2.45 GHz).



7/29/2019 IJEST11-03-10-197

8/19

Fig. 15 Block diagram of the conventional and the proposed rectennas.

Fig. 16 Measured return losses of the microstrip circular sector and square patch antennas.

Fig.17. Efficiency versus input power at A with four variable resistor values.

J. Y. Park, S. M. Han and T. Itoh [20] proposed a rectenna designed with a microstrip harmonic rejection

circular sector antenna at 2.4 GHz. A typical rectenna is shown in Fig. 15. The circular sector antenna with asector angle of 240 and an inset feeding point at 30 from the edge avoids the radiations of harmonics. Thus

low pass filter which cause insertion loss for the fundamental frequency can be eliminated. Fig. 16 shows thatreturn loss at 2

ndand 3

rdharmonics of circular sector antenna are very high. Therefore high efficiency rectenna

can be designed having maximum conversion efficiency of 77.8% using a 150 load resistor as shown in Fig.17.

IV. CIRCULARLY POLARIZED

For satellite power transmission as well as portable application, CP has more fade resistant than linearpolarization (LP) and low polarization loss between transmitting and receiving antennas without regarding itsrotating angle. The combination of CP property and harmonic rejection would bring the advantages of lowpolarization loss, conversion efficiency enhancement and simpler design. T.C. Yo et al. proposed a compact CP



7/29/2019 IJEST11-03-10-197

9/19

rectenna with two unbalanced circular slots and 2nd

order harmonic rejection property [21]. It operated at 2.45GHz with measured BW of 137 MHz and minimum 1.5 dB AR. The used double rectifier gives 78% of RF to dcconversion efficiency at 16.5 mW/cm2 incident power density and 1 K load resistance while the optimum DCvoltage output is 15.8 V. The double output voltage is generated by storing change at series capacitor Cs during

negative phase of RF signal through the shunt diode while change in Cs is accumulated with input potentialduring positive signal by turning on the series diode. The rectenna can provide good efficiency of 53% and 75%

in uncontrolled and controlled environment respectively. The doubler layer configuration and circular slotstructure make the rectenna much small (12% of size reduction) and compact (2.4 mm in thickness).

M. Ali, G. Yang and R. Dougal [22] proposed a CP microstrip patch antenna that can be used either WLAN

antenna in the 5.15-5.35 GHz or as a rectenna at 5.5 GHz. The wide axial ratio BW can be achieved by tworectangular slot positioned along the diagonal of square patch antenna which also create two hybrid operating

mode that is very close in frequency. A12.4% returns loss BW, 12.1% of axial ratio BW and 57.3% ofconversion efficiency for a load of 300 can be achieved. Computed E field of proposed antenna is shown inFig.18.

Fig. 18 Computed E field distribution of the proposed antenna on 175-mm-thick Duroid 5880 substrate at 5.5 GHz

They also designed a miniature CP rectenna operating at 5.5 GHz in year 2006, which reduces out of bandharmonic emission with the help of integrated BRF and schematic is shown in Fig. 19. The conversion

efficiency of the CP rectenna is given by

=

(5)Where;

= Transmit Power; = Gain of rectenna= Gain of the Transmitting Antenna= Polarization loss factor; = output voltage



7/29/2019 IJEST11-03-10-197

10/19

Fig. 19 Miniature rectenna with filter

The output voltage and conversion efficiency of this rectenna are shown in Fig. 20. It has a conversionefficiency of 74% with more than 50 dB out of band harmonic suppression at 11 GHz, therefore can be used for

data communication with 5.15-5.35 GHz [24].

Fig. 20 Measured output voltage (a)VD versus distance and (b) Conversion efficiency versus power density at 5.5 GHz.

R.H. Rasshofer, M. O. Thieme and E. M. Biebl proposed a silicon integrated W- band rectenna for use in 6-port polarimetric radar system. This rectenna applies with dual patch antenna layout, which permits the receiverto be manufactured by using monolithic integration [23]. Using as a receiver, an excellent cross polarizationdiscrimination >14 dB at 76 GHz over a wide range of the scan angle (12dB 20) was found, Fig. 21.



7/29/2019 IJEST11-03-10-197

11/19

Fig. 21 Measured XPD of the CP receiver chip versus frequency.

V. HIGH EFFICIENCY

B. Strassner and K. Chong [25] proposed a new CP high gain high efficiency rectenna array designed in acoplanar stripline circuit. And found that each antenna has a CP gain of 11 dB and better than 1 dB axial ratio

fractional BW of 4.7%. The single element antenna uses a CPS band reject filter to suppress the reradiatedharmonic by more than 19 dB and achieve 81% RF to dc conversion efficiency at 5.71 GHz. Whereas 3 x 3rectenna array produces 0.86 W of dc output power with an RF to dc conversion efficiency of 78% and an axialratio of 0.25 dB for an incident CP power density of 7.6 mW/cm2 at 5.61 GHz. The measured RF to dcconversion efficiency of single element rectenna and array at 5.71 and 5.61 GHz respectively are shown in Fig.22 and Fig. 23.

Fig. 22 Measured single element rectenna efficiency curves at 5.71 GHz and d = 10 mm for 50 incremental loading. Calculated curves

are shown for the 50 and 200 loading.

Fig. 23 Array RF-to-dc conversion efficiency versus CP power density at 5.61 GHz for various array loading (R ).

However in 2002, Y. H. Suh and K. Chang proposed a dual frequency printed dipole rectenna suitable for

the wireless power transmission at 2.45 and 5.8 GHz (Industrial-Scientific- Medical bands). The conversionefficiency more than 77% over the entire ISM band located between 5.725-5.875 GHz was observed [26]. The



7/29/2019 IJEST11-03-10-197

12/19

RF to dc conversion efficiency for dual frequency antenna which shows that the conversion efficiency at freespace is 84.4 and 82.7% at 2.45 and 5.8 GHz respectively is shown in Fig. 24.

(a)

(b)

Fig.24 RF-to-dc conversion efficiency for dual-frequency rectenna.(a) Efficiency and dc output voltage versus received power.

(b) Efficiency versus power density.

J. O. Mcspadden, L. Fan and K. Chang [27] designed a high efficient rectenna element, in which operationof antenna element can be better understood by analyzing the diode dc characteristics with an impressed RF

signal. They used a silicon Schottky barrier mixer diode with a low breakdown voltage as the rectifying deviceand it was found that the RF to dc conversion efficiency of 82% at an input power level of 50 mW and 327 load. The diode junction waveform can be expressed as

= cos(6)

= . . (7)Where; = Output self bias dc voltage across the resistive load.= Peak voltage of the incident microwave signal.The forward bias turn on angle on is a dynamic variable dependent on the diodes input power and is given

by

tan =

(8)



7/29/2019 IJEST11-03-10-197

13/19

Where; and are the diode series and load resistance. The antenna has good impedance matching andVSWR is less than 1.3. The power level is 21 dB down from the fundamental input power at 2nd harmonics. The

proposed rectenna found very useful at 5.8 GHz for application involving MPT.

VI. DUAL FREQUENCY

With the usage of multiple frequency bands in wireless communication systems, some dual-frequencyrectenna have been developed. In these designs, the antenna elements usually have a dimension of onewavelength length or even more.Y. J. Ren, M. F. Farooqui and K. Chang proposed a novel dual frequencyrectifying antenna operating at 2.45 and 5.8 GHz [28]. Rectenna consists of two compact ring slot antenna, a

hairpin LPF and a rectifying circuit. By using meander line structure in annual slot ring antenna, the sizereduction upto 52% was observed, whereas 2

nd and 3rd harmonics of both operating frequency was suppressed

by hairpin filter. It was found that the Rectenna has gain of 2.19 and 3.6 dBi while RF to dc conversionefficiency of 65% and 46% at 2.45 and 5.8 GHz respectively when power density is 10Mw/cm

2.

However, J. Heikkinen and M. Kivikoski proposed a novel dual frequency CP shorted ring slot antenna forWPT at 2.45 and 5.8 GHz. It was composed of two nested microstrip fed shorter annular ring slot antenna andtwo rectifier circuits. The circuit diagram of rectifier is given in Fig. 25 while component values are summarized

in Table.2. At a maximum distance of 2 m, output dc voltage of over 2 V at the lower frequency band and over 1

V at the higher frequency band can be achieved [29]. It was also found that the axial ratio of 2.2 Db in lowerband while 1.3 Db in higher band as shown in Fig. 26.

Fig. 25 Circuit diagram of the rectifier circuit.

TABLE II

RECTIFIER CIRCUIT DIMENSIONS AND COMPONENT VALUES



7/29/2019 IJEST11-03-10-197

14/19

Fig. 26 Upper graph: output dc voltage and axial ratio of the low-band rectenna. Lower graph: output dc voltage and axial ratio of the high-

band rectenna.

T. W. Yoo and K. Chang [30] proposed a rectenna with 39% conversion efficiency at 35 GHz and found that60% conversion efficiency can be achieved at 10 GHz by using a microstrip dipole antenna and mixer diode, asshown in Fig. 27.

Fig. 27 10 GHzto dc conversion efficiency of a Ka-band diode measured with 120 dc load.

VII. ISM FREQUENCY 5.8 GHz

Y. J. Ren and K. Chong proposed two new CP retro directive rectenna array having a 2x2 array and 4x4arrays [31]. They used a proximity coupled microstrip ring antenna as the array element, which can block

signals upto 3rd

order harmonics from reradiating by the rectifying circuit and thus no BPF required. It has CPgain of 5.89dB and an AR of 1.7dB. At the broadside, 73.3% and 55% conversion efficiency for 2x2 and 4x4rectenna array has found for 10mW/cm

2incident power density. The dc output voltage is 2.48 and 8.59V

respectively and almost constant within 10 of the incident angle. This technique is very suitable for the WPTwith a high gain, but narrow beam width transmitting antenna.

They also designed a 5.8 GHz dual diode rectenna and its array [32]. A truncated dual patch antenna has aCP gain of 6.38 dB and an AR of 0.42 dB. A coplanar stripline BPF was used to suppress the harmonic signalsgenerated from the diode by over 32 dB, which can block 2

ndand 3

rdharmonics. It was found that for dual diode

rectenna the maximum efficiency is 76%. The measured dc output voltage of the dual diode and rectenna arrayare shown in Fig. 28 and Fig.29.



7/29/2019 IJEST11-03-10-197

15/19

Fig. 28 Measured dc output voltages of the dual-diode and single-shunt diode rectennas.

Fig. 29 Measured dc output voltage of the rectenna array.

C. H. K. Chin, Q. Xue and C. H. Chan proposed a novel finite ground coplanar waveguide high gainrectenna element having conversion efficiency of 68.5% at 5.8 GHz with an input power of 18 dBm [33]. Theantenna used for this rectenna has the similar characteristics as of the two element array. It generates a similar

radiation pattern but radiates a higher gain of 9 dBi. It was found that the compact CPW resonant cell (CCRC)which is used as an input band stop filter, effectively suppress the 2 nd harmonic radiation. It was also found that

by using CCRC the RF to dc conversion efficiency is enhanced by 6% with a 270 load resistance.

J. Heikkinen and M. Kivikoski [34] proposed a novel CP shorted annular ring slot rectenna on a 0.5mm thickflexible microwave laminate. And found that output dc voltage of 1.3V and axial ratio is 1.5dB for 32 dBmicrowave power transmission over a distance of 2m at 5.8 GHz. Measured rectifier and rectenna output dcvoltage are plotted in Fig. 30 and Fig. 31. This rectenna is useful as a virtual battery where the receiver is

rotating relative to the transmitter.

Fig. 30 Measured rectifier output dc voltage (Vout) and efficiency (Eff) at two different input power (Pin) levels.



7/29/2019 IJEST11-03-10-197

16/19

Fig. 31 Measured rectenna output dc voltage (Vout) and axial ratio at two different transmission distances and transmitted power levels (Pt).

B. Strassner and K. Chang proposed a new CP high gain, high efficiency rectenna which can be rotated andstill maintain a constant dc output voltage. A Schottky diode is used and with this the RF to dc conversion of80% with input power of 100mW and a load resistance of 250 can be achieved [35]. It was found that a highgain dual rhombic loop antenna and a reflecting plane are used to achieve a CP gain of 10.7 dB and a 2:1 VSWR

BW of 10%. The CP gain of the proposed rectenna is given as

= (9)Where,

-Linearly polarized gain.Gain correction factor (GCF) =20 . (10)

The rectenna pattern has an elliptical cross section with orthogonal beam width of 40 and 60. It hascoplanar stripline BRF which suppress the reradiated harmonics by 20 dB. The measured diode efficiency and

output voltage verses input power for various loads are shown in Fig.32.

Fig. 32 Directly measured diode conversion efficiency and output voltage versus power delivered to the diode for various load resistances.

After one year, they also proposed a RHCP travelling wave low power density rectenna [36]. It uses dualrhombic loop antenna having a CP antenna gain of 14.6 dB with a 2 : 1 VSWR BW of 17% and a better than 3dB axial ratio fraction BW of 7% centered about 5.8 GHz. It has 82% of RF to dc conversion efficiency. Fig.33and Fig. 34 shows the return loss and axial ratio of DRLA + filter + balun circuit, while RF-to-dc conversion

efficiency for various resistive loading is shown in Fig.35. The capacitor blocks the RF energy by more than 17dB and the CPS BRF suppress the 2

ndharmonics by 14 dB below the peak fundamental gain.



7/29/2019 IJEST11-03-10-197

17/19

Fig. 33 Return loss for DRLA + filter + balun

(a)

(b)

Fig. 34 Measured DRLA + filter + balun circuit axial ratio: (a) versus frequency and (b) versus incident angle.

Fig. 35 RF-to-dc conversion efficiency for various resistive loading.

W. H. Tu, S. H. Hsu and K. Chang [37] proposed a 5.8 GHz rectenna using a stepped impedance dipoleantenna and by using it a 23% of length reduction was achieved. The configuration of rectenna using stepped



7/29/2019 IJEST11-03-10-197

18/19

impedance dipole is shown in Fig.36. It was found that a maximum conversion efficiency of 76% at 5.8 GHzwith a load of 250 can be achieved. It was also found that the conversion efficiency from 5.725 to 5.875 GHzrange is better than 67%, which cover the entire 5.8 GHz ISM band.

Fig.36 Configuration of the compact 5.8-GHz rectenna using a Stepped impedance dipole.

VIII. CONCLUSION

Therefore paper describes the progressive development of rectenna in terms of its applications in various

fields; Microwave Power Transmission, Circularly Polarized Radiation, High Efficiency and Dual Frequency

characterstics in the range of ISM as well as other high frequency bands.Theproposed rectennas comprising

several antennas such as dipole, arrays, slot, meander line, annular ring and rombhic loop antennas along with a

rectifying diode. In some cases more than one rectifying devices have also been used which causes the dual

band operations and better efficiency. The maximum efficiency as microwave power transmission was found to

91 % with 1.2 W of input power while in case of harmonic rejection, rectenna designed with circular sector

antenna provides conversion efficiency of 77.8 % with 150 load and very high return loss at 2nd and 3rd

harmonics.The RF to dc conversion efficiency for circularily polarized is 78% at 16.5 mW/cm2 incident power

density while in case of dual frequency the RF to dc conversion efficiency of 65% and 46% are achieved at 2.45

GHz and 5.8 GHz respectively when power density is 10mW/cm2.

REFERENCES

[1] W. C. Brown et al.,U.S. Patent 3 434 678, Mar. 25, 1969.[2] W. C. Brown, Experiment in the transport of energy by microwavebeam, in IEEE Inr. Conv. Rec.,vol. 12, pt. 2, Mar. 1964, pp. 8-

18.

[3] ---, Experiments involving a microwave beam to power and position a helicopter,IEEE Trans. Aerosp. Electron. Syst.,vol. AES- 5,no. 5,pp. 692-702, Sept. 1969.

[4] --- , Solar Power Satellite Program Rev. DOE/NASA SatellitePower System Concept Develop. Evaluation Program, Final Proc.Conf. 800491, July 1980.

[5] W. C. Brown, The history of power transmission by radio waves,IEEE Trans. Microwave Theory Tech., vol. MTT-32, pp. 12301242,Sept. 1984.

[6] J. Schlesak, A. Alden and T. Ohno, A microwave powered high altitude platform, inIEEE MTT-S Int. Microwave Symp. Dig.,1988,pp. 283-286.

[7] W. C. Brown, Performance characteristics of the thin-film, etched circuit rectenna, in IEEE MTT-S Int. Microwave Symp. Dig.,1984,pp. 365-367.[8] J. J. Nahas, Modeling and computer simulation of a microwave-to-dc energy conversion element, IEEE Trans. Microwave TheoryTech., vol. 23, no. 12, pp. 1030-1035, Dec. 1975.

[9] W. C. Brown and E. E. Eves, A microwave beam power transferand guidance system for use in an orbital astronomy supportfacility, Final Report (Phase 11) to NASA, NAS-8-25374, Sept. 1972.

[10] G. P. Boyakhchyan et al.,Analytical calculation of a high-efficiency microwave rectifier employing a Schottky-barrier diode,Telecom. Radio Engin.(English Translation of Elaktrosvyaz, and Radiotekhnika) vol. 37-38, no. 10, pp. 64-66, Oct. 1983.

[11] W. C. Brown, All electronic propulsion key to future space ship design, presented atAIAA/ASME/SAE/ASEE 24th Joint PropulsionConf., Boston, July 1988.

[12] James O. McSpadden, Taewhan Yoo and Kai Chang, Theoretical and Experimental Investigation of a Rectenna Element for MicrowavePower Transmission,IEEE Trans. Microwave Theory Tech., vol. 40,no. 12, pp. 2359-2366, (1992).

[13] Karl M. Strohm, Josef Buechler, and Erich Kasper, SIMMWIC Rectennas on High-ResistivitySilicon and CMOS Compatibility ,IEEE Trans. Microwave Theory Tech., vol. 46,no. 5, pp. 669-676, (1998).

[14] Larry W. Epp, Abdur R. Khan, Hugh K. Smith and R. Peter Smith, A Compact Dual-Polarized 8.51-GHz Rectenna for High-Voltage(50 V) Actuator Applications,IEEE Trans. Microwave Theory Tech., vol. 48,no. 1, pp. 111-120, (2000).

[15] J. A. G. Akkermans, M. C. van Beurden,G. J. N. Doodeman, and H. J. Visser, Analytical Models for Low-Power Rectenna Design,IEEE Antennas and Wireless Propogation Letters, vol. 4, pp. 187-190, (2005).



7/29/2019 IJEST11-03-10-197

19/19

[16] B. Essakhi, L. Pichon, and G. Akoun, Fast Analysis of a Broad-Band Microwave Rectenna Using 3-D FEM and PadApproximation,IEEE Trans. Magnetics, vol. 43,no. 4, pp. 1309-1312, (2007).

[17]Naoki Shinohara and Hiroshi Matsumoto, Experimental Study of Large Rectenna Array for Microwave Energy Transmission,IEEETrans. Microwave Theory Tech., vol. 46,no. 3, pp. 261-268, (1998).

[18] Joseph A. Hagerty,Florian B. Helmbrecht,William H. McCalpin, Regan Zaneand Zoya B. Popovic, Recycling Ambient MicrowaveEnergy WithBroad-Band Rectenna Arrays,IEEE Trans. Microwave Theory Tech., vol. 52,no. 3, pp. 1014-1024, (2004).

[19] A. Georgiadis, G. Andia and A. Collado, Rectenna Design and Optimization Using Reciprocity Theory and Harmonic BalanceAnalysis for Electromagnetic (EM) Energy Harvesting, IEEE Antennas and Wireless Propogation Letters, vol. 9, pp. 444-446,(2010).

[20] Ji-Yong Park, Sang-Min Han and Tatsuo Itoh, A Rectenna Design With Harmonic-Rejecting Circular-Sector Antenna, IEEEAntennas and Wireless Propogation Letters, vol. 3, pp. 52-54, (2004).

[21] Tzong-Chee Yo, Chien-Ming Lee, Chen-Ming Hsu, and Ching-Hsing Luo, Compact Circularly Polarized Rectenna With UnbalancedCircular Slots ,IEEE Trans. Antennas Propagate., vol. 56,no. 3, pp. 882-886, (2008).

[22] Mohammod Ali, Guangli Yangand Roger Dougal,Miniature Circularly Polarized Rectenna With Reduced Out-of-Band Harmonics,IEEE Antennas and Wireless Propogation Letters, vol. 5, pp. 107-110, (2006).

[23] Mohammod Ali, G. Yang and R. Dougal, A New Circularly Polarized Rectenna for Wireless Power Transmission and DataCommunication,IEEE Antennas and Wireless Propogation Letters, vol. 4, pp. 205-208, (2005).

[24] Ralph H. Rasshofer, Markus O. Thieme and Erwin M. Biebl, Circularly Polarized Millimeter-WaveRectenna on Silicon Substrate ,IEEE Trans. Microwave Theory Tech., vol. 46,no. 5, pp. 715-718, (1998).

[25] Berndie Strassnerand Kai Chang,, Highly Efficient C-Band Circularly Polarized Rectifying Antenna Array for Wireless MicrowavePower Transmission,IEEE Trans. Antennas Propagate., vol. 51,no. 6, pp. 1347-1356, (2003).

[26] Young-Ho Suh and Kai Chang, A High-Efficiency Dual-Frequency Rectenna for2.45- and 5.8-GHz Wireless Power Transmission,IEEE Trans. Microwave Theory Tech., vol. 50,no. 7, pp. 1784-1789, (2002).

[27] James O. McSpadden, Lu Fan and Kai Chang, Design and Experiments of a High-Conversion-Efficiency 5.8-GHz Rectenna, IEEETrans. Microwave Theory Tech., vol. 46,no. 12, pp. 2053-2060, (1998).

[28] Yu-Jiun Ren, Muhammad F. Farooqui, and Kai Chang, A Compact Dual-Frequency Rectifying Antenna With High-OrdersHarmonic-Rejection,IEEE Trans. Antennas Propagate., vol. 55,no. 7, pp. 2110-2116, (2007).

[29] Jouko Heikkinen and Markku Kivikoski, A Novel Dual-Frequency Circularly Polarized Rectenna, IEEE Antennas and WirelessPropogation Letters, vol. 2, pp. 330-333, (2003).

[30] Tae-Whan Yoo and Kai Chang, Theoretical and Experimental Development of 10 and 35 GHzRectennas,IEEE Trans. MicrowaveTheory Tech., vol. 40,no. 6, pp. 1269-1276, (1992).

[31] Yu-Jiun Ren and Kai Chang, New 5.8-GHz Circularly Polarized Retrodirective Rectenna Arrays for Wireless Power Transmission ,IEEE Trans. Microwave Theory Tech., vol. 54,no. 7, pp. 2970-2976, (2006).

[32] Yu-Jiun Ren and Kai Chang, 5.8-GHz Circularly Polarized Dual-Diode Rectenna and Rectenna Array for Microwave PowerTransmission,IEEE Trans. Microwave Theory Tech., vol. 54,no. 4, pp. 1495-1502, (2006).

[33] Ching-Hong K. Chin, Quan Xue and Chi Hou Chan, Design of a 5.8-GHz Rectenna Incorporating a New Patch Antenna, IEEEAntennas and Wireless Propogation Letters, vol. 4, pp. 175-178, (2005).

[34] Jouko Heikkinenand Markku Kivikoski, Low-Profile Circularly Polarized Rectifying Antenna for Wireless Power Transmission at5.8 GHz,IEEE Microwave and Wireless Components Letters, vol. 14, no. 4, pp. 162-164, (2004).

[35] Berndie Strassnerand Kai Chang, 5.8-GHz Circularly Polarized Rectifying Antenna for Wireless Microwave Power Transmission, IEEE Trans. Microwave Theory Tech., vol. 50,no. 8, pp. 1870-1876, (2002).

[36] Berndie Strassnerand Kai Chang, 5.8-GHz Circularly Polarized Dual-Rhombic-Loop Traveling-Wave Rectifying Antenna for LowPower-Density Wireless Power Transmission Applications,IEEE Trans. Microwave Theory Tech., vol. 51,no. 5, pp. 1548-1553,(2003).

[37] Wen-Hua Tu, Shih-Hsun Hsu, and Kai Chang, Compact 5.8-GHz Rectenna Using Stepped-Impedance Dipole Antenna, IEEEAntennas and Wireless Propogation Letters, vol. 6, pp. 282-284, (2007).


ISSN 0975 5462 V l 3 N 10 O t b 2011 7841

ijest11-03-10-197

Documents