A Hybrid Coupler Integrated 1×4 Printed Array Antenna with Broadband and High Performance For Beamforming RFID Reader

This paper suggests a broadband, high gain, large coverage 1×4-array antenna for 2.45 GHz radio frequency identification (RFID) reader applications. Initially, to maintain the compactness, a miniaturized basic patch element is designed with minimal return loss, good gain and high radiation efficiency. Based on the miniaturized single patch element, an array antenna with lx2 configuration has been designed and optimized. Afterwards, a hybrid coupler is used to feed the radiating patches of the miniaturized lx2 array antenna. The proposed antenna offers broadband radiation characteristics with a high gain, high radiation efficiency, and switchable main beams due to the proposed arrangement of the feeding network. Morever, it generates flexible beam directions having an extensive broad operating ranging from 1.725 GHz to 2.960 GHz with an impedance bandwidth of 1250 MHz, peak gain and radiation efficiency of 11.26 dB, and 99.52%, respectively. It can also radiate in two different regions (−30° & + 30°) by switching the connected ports of the two input feeds of the hybrid coupler. The structural design has been executed on a 1.56 mm thick Rogers RT/duroid 5880 Substrate with a physical area of 240×136mm
²
with the help of the HFSS simulator. The results achieved with HFSS software are re-verified by CST simulator.