paper uhf rfid reader

Design & Development of Low Cost UHF RFID Reader

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Lalit Kumar, Chandan Maity, Arivendu Bhardwaj, Adarsh Pillai, H.P. Srivastava, Rakesh Kumar

Abstract : This paper describes the design & development of low cost Ultra High Frequency (UHF) RFID Reader. It consists of three different modules Power supply, Microcontroller and Transceiver. The transceiver module uses the UHF RFID reader chip to interface with microcontroller module and power amplification module. Keywords: RFID - Radio Frequency Identification.

1. Introduction Radio Frequency Identification (RFID) is an auto-ID technology that identifies any object that contains a coded tag. A UHF RFID system consists of a reader ( or interrogator) that transmits information to a tag by modulating an RF signals in the 860MHz-960MHz frequency range [1]. UHF RFID readers are becoming more highly integrated and innovative. Reader integrated circuits (ICs) have come to lead the market for UHF RFID, enabling these technologies to be integrated into smaller, more power-efficient devices [3]. The EPC global Gen 2 passive UHF RFID standard has proved to be functional and robust [2]. Department of Information Technology (DIT), Government of India, has sponsored a project titled “National RFID Programme”, to popularize the use of RFID technology in different applications areas in the country. This is a multi-institution project involving CDAC, Noida, IIT Kanpur and SAMEER, Mumbai. The current project on development of the reader was undertaken as part of this. The remaining sections of this paper are organized as follows. Section 2 gives the detailed description of the UHF RFID reader. Section 3 gives the system interfaces to the external world and how it works in a network. Section 4 gives the costing aspects of the system being developed. Section 5 gives the performance of the reader. Section 6 gives the conclusion. 2. Block Level Description Of System Developed The low cost UHF RFID reader is designed using high speed ICs, RFID chip, passive and active electronics components. A 32 bit microcontroller is used to control reader functions like reading, writing of tags, adjust power gain etc [3]. UHF RFID reader is planned with three modules viz. Power supply, Microcontroller and Transceiver. These are designed and developed from initial stage i.e. from drawing schematics of circuit and development of Gerber data using art work generation then PCB fabrication and assembly of electronics components and then finally burning the software and integration. The modules are further described as follows. 2.1 Power Supply Module The module (Figure 1) will act as a power supply unit for the reader as a whole. The specific voltages used in this whole design are 1.8V, 3.3V and 5V. The power supply required to drive the ARM core and R1000 board is less than 2.2W. Power supply module generates the various voltage nodes according to the board requirement of 3.3V, 1.8 V

Proceedings of ASCNT – 2009, CDAC, Noida, India, pp. 215 – 222


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(figure 2). All the boards( MCU board, Transceiver board) normally need the voltage level of 1.8 and 3.3V DC.

Fig.1. Power supply module

Fig.2. Block diagram of power supply module Only the receiver section of R1000 chip needs 5V DC to drive high gain internal amplifier which has receiving sensitivity of arround -90 dBm. 2.2 Transceiver Module The module (Figure 3) is the heart of the system with major components as INTEL R1000 chip, Balun and Dielectric Band Pass Filter. Antenna Ports for transmission and reception of signals are available on this module. The R1000 chip is the master chip for UHF RFID reader.

Fig.3. Transceiver Module


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Fig.4. Block diagram of transceiver module It has a analog processing unit for analog RF front-end tightly coupled with digital back-end for host connectivity (Figure 4). Digital configurable registers control the R1000 chip to operate in various architecture of UHF protocol. R1000 incorporates the complete transmit, receive, modulation, demodulation and baseband functions into one chip. 2.3 Microcontroller Module A microcontroller contains a processor core, memory, and programmable input/output peripherals.

Fig.5. Block diagram of microcontroller module

This has ATMEL’s AT91SAM7S256 with ARM7 core as microcontroller. It will support the total firmware of the system which includes the Boot up, the mode of work of the reader, configuration setting of the registers etc.MCU board is the heart of the reader. It controls the R1000 based transceiver board. All the data and commands are being sent and received through 20 MHz SPI buss. The EPC-C1G2/ISO 16k6c protocol stack runs at the ARM7 core which is basically the AT91SAM7S256, the ARM7 product of Atmel. The MCU board behaves like an interfacing buffer between R1000 chip and host (normally the PC).

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2.4 UHF RFID Reader Prototype The product (Figure 6) is a UHF RFID Reader which is an integrated solution of RFID based hardware and firmware. UHF RFID Reader will read UHF EPC C1G2 RFID tags with the help of UHF antennas. This reader is based on UHF R1000 chip which is controlled by 32 bit Atmel microcontroller. Reader has 15000 6C protocol stack. This product is a high end low cost solution for UHF RFID reader.

Fig.6. UHF RFID Reader prototype 3. System Interfaces The core of the reader is the Intel R1000 UHF transceiver chip. The radio chip supports multiple antenna ports, which can be used in monostatic or bistatic mode. The firmware of this reader consists of the ARM based microprocessor, communicating with the radio through a firmware interface (APIs). The underlying hardware interface between the reader chip and ARM is based on SPI protocol. The host or the development platform can communicate with system, trough USB or JTAG interface. 3.1 Device Physical layer Interface The RFID reader consist of three modules which are interconnected (Figure 7). The MCU board consists of the ARM7 microcontroller unit which always behaves as slave for upstream interfaces like PC or other controlling unit and it behaves as master for the R1000 radio chip. Presently the upstream interfaces are RS232 or USB.

Fig.7. Physical Layer Interface


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The design of RFID reader board is enables it to be used either as a very small device like handheld UHF RFID reader or as a standalone smart reader. To make the intelligent reader it has been planned to incorporate another 32 bit processor (Figure 8) which will store and run an operating system and will control the UHF reader board and will have a lots of physical layer interface facility.

Fig.8. Intelligent Reader with another 32 bit Processor.

3.2 Software Interface Across Different Layers The firmware binaries for the Intel R1000 based, UHF RFID Transceiver, run on the ARM based firmware controller (Figure 9). For the user space applications to communicate with the firmware, there is a thin firmware interface layer, that has the required API’s and libraries specific to the R1000’s firmware. This interface layer enables the applications to be portable across IA32 and IXP465 platforms based either on Windows XP or Linux, as to port applications -coded in C language- across IA32 and IXP465 platforms, only the firmware interface libraries need to be cross compiled, and there is no need to rewrite the applications for different platforms.

Fig.9. Functional flow across different software layers


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4. Costing Aspects Tables 1,2 and 3 shows the development cost of each module viz. Power supply board, Microcontroller board and Transceiver Board respectively. 4.1 Power Supply Board

Table1. Development Cost of Power Supply Board S.N. Name of Main Components Amount in

Rs. 1. Regulators(3x50) 150 2. PCB & Assembling 700 3. Misc 500

Total Cost Rs. 1350

4.2 Microcontroller Board Table2. Development Cost of Microcontroller Board

S.N. Name of Main Components Amount in Rs.

1. MCU 1000 2. Temp Sensor 100 3. MOSFET 100 4. Misc 2500 5. PCB & Assembling 700

Total Cost Rs 4400 4.3 Transceiver Board

Table3. Development Cost of Transceiver Board S.N. Name of Main Components Amount in

Rs. 1. R1000 2800 2. Coupler 1200 3. Baluns 200 4. SMA_Plug 100 5. Oscillator 600 6. PCB & Assembling 700 7. Misc 5900

Total Cost Rs 11500 4.4 Other expenses Other expenses include single time PCB design(stencil), shipping charges of components and metallic or PVC Box fabrication to shield the reader and label etc. Total Cost Rs. 3800/- (Approximate) 4.5 Total cost of the Reader The expected cost of complete reader will be approximately Rs. 21050 which will be facilitated with all the features comparable with any standard available reader. The development cost of amplifier circuit is not included.

5. Performance of the Reader The major hurdle of the UHF RFID reader development is the protocol stack for ISO/EPC standard. In the prototype model the EPC-C1G2/ ISO180006C has been implemented and


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the reader is communicating with tag fairly with a distance of 5-6 cm. The Power amplifier module has to be added with the base model to get the maximum allowable output power and corresponding large distance. The output power of 30 dBm with 6 dBi antenna and the receiver sensitivity of -90dBm will make the reader to compare with any highly standard reader.

6. Conclusion By developing Intel R1000 based UHF RFID reader, we are providing alternate to the existing high cost UHF RFID reader. This product will drastically reduce the total cost of the existing RFID readers. Acknowledgement This paper is the result of research efforts for the Development of a Low Cost UHF RFID reader as a sub project under the National RFID Programme which is sponsored and funded by the Department of Information Technology (DIT), Government of India and CDAC, Noida. The author expresses his gratitude to the DIT, Government of India and CDAC management committee for giving the opportunity to work on this project. References

[1] Secrets of RF circuit Design By Joseph J. Carr, Tata McGraw-Hill [2] RFID Essentials By Bill Glover & Himanshu Bhatt O’Reilly [3] www.intel.com/products/embedded/rfid About Authors Mr. Lalit Kumar received his Bachelor’s degree in Computer Science &

Engineering, from KIET Ghaziabad, Dr. B R Ambedkar University, Agra, UP, India. He joined BEL Ghaziabad in 2004 and worked on EMCCA and CAIO Projects and Battlefield Surveillance System Project in Central Research Lab. He joined CDAC NOIDA in 2005, and presently working here in R&D as a Project Engineer in Embedded Systems Lab. He has worked on Design and Development (core level ) of small Linux Operating system for Browser Based Digital Set Top Box and Linux internals. He is presently working as a team leader in the UHF RFID domain and developed low cost UHF RFID Reader. His areas of interest include Embedded Linux and kernel internals.

Mr. Chandan Maity received BE degree in Electrical Engineering from the Burdwan University, WB, India. Presently he is a research Fellow in CDAC, Noida, India in Embedded system dept. He served as executive electrical engineer in wartsila india Ltd., as Research associate in IIT Kanpur, India. He took the responsibility as R&D and technical head in Iaito Infotech Pvt. Ltd, Kanpur, India. His interests cover the domain of RFID, GSM, AI, Sensor Network, Mobile computing, Ubiquitous system.


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Mr. Arivendu Bhardwaj received his Bachelor’s degree in Electronics

and Communication, from Kurukshetra University, Kurukshetra, and P.G Diploma in Embedded Systems and VLSI Design, from CDAC NOIDA. He joined CDAC NOIDA in 2005, and presently working here as a Project Engineer, in Embedded Systems Lab. He has worked on system programming for 8/16 bit micro controllers, GSM/GPRS engine, IP Set top Box and Linux internals. He is presently working in the UHF RFID domain, involving single chip RFID Radio and ARM firmware controller. His areas of interest include ARM architecture, Linux kernel internals and inter chip communication protocols.

Mr. Adarsh Pillai received his Bachelors of Engineering in Electronics and Communication from Maharishi Dayanand University, Rohtak, India in 2004 and Post Graduation in Embedded and VLSI Design from C-DAC, Noida in 2006. Presently he is working as Project Engineer in Ubiquitous computing Group at C-DAC, Noida. He has worked with Reliance Communications, Noida as Deployment Engineer in Fixed Access Team. His main interest covers working on EDA tools, Embedded C programming and Linux Internals.

Mr. H P Srivastava received his two years Diploma in Electronics. He joined C-DAC Noida in 1994. He is presently working as Sr. Technical Assistant in Ubiquitous Computing group at C-DAC, Noida. He has been involved in various projects like cable modem, uninterrupted power supply and Set Top Box etc. and he involved in designing the PCB of UHF RFID Reader. His area of interest covers the multilayer PCB Layout design using EDA tools.

Mr. Rakesh Kumar received his A.M.I.E Degree in Electronics & Communication Engineering from The Institution of Engineers (India). He joined C-DAC, Noida in Jan 2007.Presently he is working as Contract Engineer(II) in the Ubiquitous Computing Group. He has been involved in various projects of R&D. Previously he was involved in numerous fields like Microprocessor, Analog & Digital Electronics, Power Electronics, Microwave, Optical Fiber Communication and Analog & Digital Communication. His area of interest covers RFID technology and PCB Designing using EDA tools.

paper uhf rfid reader

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