Ambient Backscattering Transponder with Independently Switchable Rx and Tx Antennas

Abstract

This article presents an ambient backscattering transponder with independently beam-switchable receive and transmit antennas. The independently switchable antennas make it possible to collect ambient waves from the direction where they are the strongest and further modulate and redirect the waves toward the receiver possible in a direction other than the ambient source. The transponder consists of patch antennas, circulators, low-power RF switches, and a diode-based modulator.