Abstract The persistent demand for compact and high‐performance UHF RFID readers presents a significant design challenge, often forcing a trade‐off between antenna gain and physical footprint. This paper presents a novel multilayer antenna that achieves simultaneous gain enhancement and miniaturization. The proposed design, operating at 867 MHz, comprises an FR‐4 substrate for the radiating element, a solid ground plane, and a pivotal middle layer fabricated from PDMS. The PDMS interlayer is placed between the FR‐4 radiator and the ground plane, where it provides dielectric loading and controls the radiator‐to‐ground spacing, enabling an approximately 30% physical dimension reduction while supporting improved boresight realized gain. To validate the design, a prototype has been fabricated and experimentally characterized. Measurement results show a strong correlation with full‐wave simulations, achieving a realized gain of 4.6 dBi and a return loss of −17.35 dB at the target frequency. Furthermore, system‐level performance was evaluated in a realistic open‐air area test, where the antenna demonstrated a maximum read range of 7.2 m with a commercial RFID reader. The proposed antenna demonstrates a compelling and well‐balanced trade‐off between high realized gain, a moderately compact form factor, and robust operational performance, presenting the PDMS interlayer as an effective design element for modern UHF RFID reader antenna implementations.
Cem Gocen (Sun,) studied this question.