Further Investigation of a Frequency-Reconfigurable Transponder on the Basis of a Mutually Coupled Antenna Cluster and Phased Modulators

In this article, a frequency-reconfigurable transponder on the basis of the antenna cluster and phased modulators is presented. Frequency reconfigurability is obtained through a cluster of mutually coupled antenna elements of variable length. The approach benefits from mutual coupling instead of avoiding it. By optimally delaying the modulated reflected signal at each antenna element in the time domain (i.e., phase shift in the frequency domain) through the modulation delay, the backscattered signal power can be maximized at a given frequency. The broadband transponder is intended to function over a wide frequency range of 1 GHz to 6 GHz.