A Novel Low Sidelobe Level Uniform Transmit/Receive Antenna Arrays for RFID Applications

The presence of higher minor lobes in RFID reader antennas results in interference, while the utilization of separate antennas for transmission and reception increases the hardware cost and complexity.To address these limitations, a shared aperture antenna array with low sidelobe levels (SLLs) using a two-way array factor is presented.The proposed array utilizes uniform feeding for both the transmit and receive arrays to minimize the design feeding network complexity.The combinatorial analysis is used to turn OFF some of the receive array elements, placing its nulls with the peak SLLs of the transmit array, ensuring optimum suppression in the peak SLL of the twoway array pattern.The proposed antenna array achieves a significant improvement in SLL of about 14.9 dB at the cost of only 1.12 dB loss in the directivity compared to the conventional arrays.Furthermore, about 9 dB and 0.28 dB improvement in SLL and directivity, respectively, is observed compared to the state-of-the-art solutions.