Circularly Polarized Suspended Patch Antenna Fed by Modified L-Probe for UHF RFID Reader

K S Cheng,E H Lim,Y N Phua

doi:10.13164/re.2017.1033

Abstract

Circularly Polarized Suspended Patch Antenna Fed by Modified L-Probe for UHF RFID Reader

Highlights

Radio-frequency identification (RFID) is an emerging technology that uses electromagnetic waves to extract information stored in a tag placed on an object
The regulated ultra-high frequency (UHF) RFID spectrum is 902 MHz to 928 MHz for the United States, 919 MHz – 923 MHz for Malaysia, 952 MHz – 956.4 MHz for Japan, and 866 MHz – 869 MHz for Europe and others. It is very desirable for a UHF RFID reader antenna to have wide bandwidth and good circular polarization (CP) so that the tag will not be affected by its orientation
The reflection coefficient is measured using an R&S® ZVB8 Vector Network Analyzer (VNA), and the read range of the proposed antenna is measured by connecting the antenna to a commercially available UHF reader Mi-1801B, where the power of the reader is set to be 30 dBm

Summary

Introduction

Radio-frequency identification (RFID) is an emerging technology that uses electromagnetic waves to extract information stored in a tag placed on an object. The regulated UHF RFID spectrum is 902 MHz to 928 MHz for the United States, 919 MHz – 923 MHz for Malaysia, 952 MHz – 956.4 MHz for Japan, and 866 MHz – 869 MHz for Europe and others It is very desirable for a UHF RFID reader antenna to have wide bandwidth and good circular polarization (CP) so that the tag will not be affected by its orientation. An L-shaped probe was deployed for exciting two slot-loaded circular patches in [16] In this case, the two patches are stacked for achieving a CP bandwidth of 14.2%. A novel and simple modified L-shaped probe feed, which consists of three wire sections, is introduced to excite an un-truncated rectangular patch for designing reader antenna for the UHF band in Malaysia. Detailed parametric analysis has been conducted to investigate the performance of the proposed antenna

Antenna and Array Configurations

Results and Discussion

Parametric Analysis

Conclusion