Ultra-low sidelobes from time-modulated arrays

TLDR

The technique is compatible with large electronically steerable phased arrays. The method uses on‑off RF switches programmed in a predetermined sequence to generate the desired pattern. Experimental tests on an eight‑element slot array show that time‑modulated switching reduces 30‑dB and 13‑dB sidelobes to about 40 dB, yielding ultra‑low sidelobe patterns.

Abstract

Antenna patterns with ultra-low sidelobes have been obtained for an experimental receiving array designed with time-modulated slot radiators. The technique utilizes on-off RF switches which are programmed in a predetermined sequence to produce the desired pattern. The results of tests on an experimental eight-element slot array designed for sidelobe reduction are presented. Two examples are considered: 1) an initial static pattern with 30-db sidelobes which are reduced to about 40 db by sequential switching and 2) an initial static pattern with 13-db sidelobes which are reduced directly to about 40 db by a different sequence of switching. Measured patterns illustrating the sidelobe reduction are included. The applicability of the sidelobe reduction technique to large electronically steerable phased arrays is considered briefly and it is concluded that it is compatible with such systems.