Optimizing Antenna Impedance Adaptation for UHF RFID Design

This paper introduces comprehensive methodologies for optimizing UHF RFID performance over-the-air. The primary objective is to enhance the effectiveness of UHF RFID tags by maximizing the mean power transmission coefficient and modulation factor, crucial intrinsic characteristics. Through a systematic investigation within a predefined $\left ({{\sqrt {M},\tau }}\right)$ , (Q, $\gamma $ ) chart, we delve into these attributes, exploring their interplay. For a given chip, we establish and illustrate the valid domain, showcasing optimal antenna impedance choices. The culmination of this process is visually depicted by transforming the chart into the impedance plane, effectively highlighting antenna impedances that concurrently maximize both the mean power transmission coefficient and the modulation factor.