Proceedings of International Conference on Microwave - 08

A Novel Inset Fed Patch Antenna Design for RFID at 2.4 GHzSanyog Rawat1 and Parul Pathak2

IAmity School of Engineering, Amity University Rajasthan (India), E-mail: 2Research Scholar,Electronics & Communication Engineering Department, Malviya National Institute of

Technology, Jaipur, Rajasthan (India)

E-mail: cparuI5@yahoo.com.sanyog44@yahoo.com

III. DESIGN

Fig. 1: Basic rectangular microstrip antenna construction.

Fig. 2: Design ofmicrostrip antenna with inset fed

____....Substtate

_______.. GrCUId

AntI!DDI-------.h

Fig.2 shows the inset fed microstrip patch antenna. Letthe substrate dielectric constant, thickness, patch length,patch width, feed line width and feed line inset distancebe denoted by Er=2.31, h =0.127 cm, L =4.14 cm (alongx-axis), W = 5.64 cm (along y-axis), Wf = 1.68 cm and y=0.19 cm respectively. Input impedance of the inset fedmicrostrip patch antenna mainly depends on the insetdistance y and to some extent on the inset width(spacing between feeding line and patch conductor).

The microstrip antenna design is simulated for S­parameters using the IE3D Simulator, and its response isshown in figures 3.

Modem communication systems demand for low costand low profile antennas. Microstrip patch antenna isone of the candidate antennas meeting thoserequirements due to its conformal nature and capabilityto integrate with the rest of the printed circuitry. Feedingmechanism plays an important role in the design ofmicrostrip patch antennas. A microstrip patch antennacan be fed either by coaxial probe or by an inset

Radio Frequency Identification or RFID refers tothe set of technologies that use radio waves foridentifying objects or people. The RFID systems allowus to identify individual objects or things in theenvironment which can be monitored through use ofwireless technology. RFID is a generic term fortechnologies that use radio waves to remotely store andretrieve data. In other words, it is a combined term withRF and ID where RF means a wireless communicationtechnology and ID means identification information oftag. So it is said that RFID is theoretically a wirelessnetworking technology to transmit identificationinformation stored at an electronic memory space [I].

Radio frequency identification tag (RFID) hasemerged as a promising technology for increasingvisibility and efficiencies in the supply chain. RFIDsystems are increasingly being employed in distributionand supply chains like Walmart and Tesco [3]. Recentlyseveral government agencies including US-DOD andFDA have issued mandates requiring suppliers to useRFID on their products [4] [5]. Apart from the industrialapplications, RFID are used for baggage tracking andaccess control. Asset tracking is a particularly usefulapplication, since RFID can help in automated trackingof high-value assets.

II. CONSTRUCTION

Abstract - Modern RFID system demands for low costand low profile antennas. Microstrip antenna offers apotential solution meeting those requirements. In thispaper a new antenna design using a inset fed that issuitable for high gain microstrip antennas is presented.

Index Terms - RFID, Microstrip Antenna, Inset Fed.

I. INTRODUCTION

A microstrip patch antenna is a radiating patch on oneside of a dielectric substrate, which has a ground planeon the underside[3]. The EM waves fringe off the toppatch into the substrate, reflecting off the ground planeand radiates out into the air. Radiation occurs mostlydue to the fringing field between the patch and ground(Fig. I).

978-1-4244-2690-4444/08/$25.00©2008 IEEE

748

Proceedings of International Conference on Microwave - 08

microstrip line. Coaxial probe feeding is some timesadvantageous for applications like active antennas,while microstrip line feeding is suitable for developinghigh gain microstrip array antennas.

FrequencylGHz'

Fig. 3: Design simulated for S-parameters using IE3D

IV. CONCLUSION

Finally, we presented results that showed good overallperformance, but expected narrowband operation.

ACKNOWLEDGMENT

The authors thankfully acknowledge the authorities ofMalviya National Institute of Technology, Jaipur.

REFERENCES

[1] ITU-T Workshop on "Networked RFID: Systems andServices" Geneva, 14-15 February 2006

[2] D. M. Pozar, "Input impedance and mutual coupling ofrectangular microstrip antennas". IEEE Trans. AntennasPropagat., vol. AP-30, pp.

[3] Laran RFID, Basic introduction to RFID technology andits use in supply chains, White paper, April 2004.

[4] Logistics and material readiness, home page:http://www.acq.osd.mil/log/rfid/index.htm. 2005.

[5] Wynne, M. W., Radio frequency identification(RFID) policy. Policy statement, The UnderSecretary of Defense, July 30 2004

749