In-Band Co-Polarization Scattering Beam Scanning of Antenna Array Based on 1-Bit Reconfigurable Load Impedance

TL;DR

This paper presents a novel method for controlling in-band co-polarization scattering in antenna arrays using 1-bit reconfigurable load impedance, enabling beam scanning with reduced radar cross section.

Contribution

It introduces a load impedance regulation technique with PIN diodes for scattering beam control and solves the dual-beam issue for single-beam scanning in antenna arrays.

Findings

Achieved scattering beam scanning within 45° range.

Designed and fabricated a 6 GHz 1×16 antenna array with 16.3 dBi gain.

Measured results match simulations, confirming effectiveness.

Abstract

Controlling the in-band co-polarization scattering of the antenna while maintaining its radiation performance is crucial for the low observable platform. Thus, this paper studies the in-band co-polarization scattering beam scanning of antenna arrays. Firstly, the regulation method of antenna scattering is analyzed theoretically, concluding that the amplitude and phase of the antenna's scattering field can be regulated by changing the load impedance. Subsequently, PIN diodes are implemented to control the load impedance of the antenna. Consequently, the scattering of the antenna, ensuring that the antenna's scattering meets the condition of equal amplitude and a phase difference of 180{\deg} when the PIN diode switches, thereby realizing scattering beam scanning. Moreover, by introducing an additional pre-phase, the inherent symmetric dual-beam issue observed in traditional 1-bit reconfigurable structures is overcome, achieving single-beam scanning of the scattering. Finally, a 1{\times}16 linear antenna array is designed and fabricated, which operates at 6 GHz with radiation gain of 16.3 dBi. The scattering beams of the designed array can point to arbitrary angles within 45{\deg}, significantly reducing the in-band co-polarization backward radar cross section. The measured results align well with the simulated ones.