The Independently Controllable Multi-beam of Time-Modulated Array

This paper presents an independent controllable multi-beam technology based on time-modulated array (TMA). Stepped waveform generated by in-phase/quadratue (I/Q) time modulation with digital attenuators is applied to present flexible time-modulated signals. It adjusts the time delay of each sideband independently to control the direction of the corresponding beams. Simulated radiation patterns at the 1st, 2nd, and 3rd sidebands are presented and other undesired sidebands are suppressed.

I. Introduction

Multi-beam antennas can transmit or receive multiple signals simultaneously with a single antenna. Through meticulous design and control, they can enhance the coverage, capacity, and reliability of communication systems, which is suitable for radar, co mmunication and many other fields. Time-modulated array (TMA) antennas can naturally generate a large number of harmonics and produce sideband multi-beams with different pointing directions. In [1], sum of weighted cosines (SWC) pulse is designed as the theoretical time-modulated signal for multi-beam TMA. By introducing in-phase/quadrature (I/Q) time modulation [2] [3] and digital attenuators [4] [5], stepped waveform modulations are used to achieve multi-beam TMA with high flexibility in practice [6].