Tri-State Sequences Control of TMAs for Multibeam Reception

A time-modulated array (TMA) is a multi-antenna system that offers the possibility of exploiting the sideband radiation patterns as steerable directional beams which can either serve a number of distributed users or exploit the multipath channel angular diversity. Unfortunately, as the number of exploited harmonic beams increases, both the antenna efficiency and the beam steering flexibility drastically decrease. In this paper, we present a novel TMA switching network based on single-pole triple throw switches controlled by tri-state sequences. The TMA allows for a flexible steering of the first positive harmonic beam and, at the same time -taking advantage of the time-multiplexed zero states of the pulses- it can additionally exploit the fundamental beam pattern, reaching an excellent total efficiency level.