2-LAYER SUBSTRATE PATCH ANTENNA WITH EBG GROUND PLANE FOR PASSIVE RFID OF METALLIC BOXES / OBJECTS IN WAREHOUSES

Abstract

"Radio frequency identification (RFID) is an integral part of our life, which increases productivity and convenience. It is the term coined for short-range radio technology used to communicate mainly digital information between a stationary location and a movable object or between movable objects. This RFID system uses the principle of modulated backscatter where it can transfer the data from the tag to the reader. The tag generally reads its internal memory of stored data and changes the loading on the tag antenna in a coded manner corresponding to the stored data.

Passive Ultra High Frequency (UHF) RFID is a promising technology for products tracking in logistics or routing packages in supply chain. However, the RFID tag is significantly affected by objects surround it especially metallic objects. In this project, a new method using Electromagnetic Band-gap (EBG) material to insulate the UHF RFID tag from backside objects, so that the tag could work even on metal. Some EBG structures include drilled holes in dielectrics, patterns etched in the ground plane, and metallic patches placed around microstrip structures.

This project attempts to design a patch antenna with EBG ground plane and two-layer substrate for passive RFID tag applications mountable on metallic objects. The performance of rectangular, circular and triangular microstrip antenna with EBG is presented and discussed. These designs were simulated using Agilent Advance Design System (ADS).

A prototype of the rectangular microstrip antenna and EBG structure is fabricated and tested to verify the analysis. The design used FR4 substrate with dielectric constant of 4.5 and height of 1.6 mm. Network Analyzer was used to measure the design. Both simulated and measured data are compared and contrasted. "