Antenna Beampattern With Range Null Control Using Weighted Frequency Diverse Array

Yi Liao,Jian Wang,Zhi Zheng,Qing Huo Liu,Hu Tang,Xiaolong Chen,Wen-Qin Wang,Mengdao Xing

doi:10.1109/access.2020.2979942

Abstract

The range-angle-dependent beampattern of frequency diverse array (FDA) makes it capable of dealing with range-dependent interference, which cannot be handled by conventional phased array. However, current publications pay more attention to the dot-shaped beam forming, which is not suitable for the range-dependent jamming signal suppression. To address this problem, this paper proposes a weight designing method to control the nulls distribution among range bins in the mainbeam. With the additional degrees of freedom provided by FDA, it is possible to flexibly adjust the positions and notch widths of the range nulls. The performance and effectiveness of the proposed weighted FDA are validated with numerical simulations.

Highlights

Frequency diverse array (FDA) is an array whose array elements have a variety of transmit frequencies, which is apparently different from the conventional phased array [1]–[3]
The array elements of frequency diverse array have different frequencies, which brings in additional degrees of freedom, leading to a range-angle-dependent beampattern [4]
frequency diverse array (FDA) was applied into synthetic aperture radar (SAR) imaging, the range-dependent beampattern increases the synthetic aperture in spotlight SAR, resulting in a higher azimuth resolution [13]

Summary

INTRODUCTION

Frequency diverse array (FDA) is an array whose array elements have a variety of transmit frequencies, which is apparently different from the conventional phased array [1]–[3]. Reference [8] studied the periodicity of the beampattern of FDA in terms of range, angle and time. FDA was applied into synthetic aperture radar (SAR) imaging, the range-dependent beampattern increases the synthetic aperture in spotlight SAR, resulting in a higher azimuth resolution [13]. Reference [15] exploited the FDA technique in space-time adaptive processing (STAP) radar to improve the range ambiguous clutter suppression. In [18], an FDA with logarithmically increasing frequency offset was proposed, the range and angle of the beam were decoupled to some extent. In order to overcome the time-dependent effect, an FDA scheme with time-dependent frequency offset was studied and a time-independent beampattern for a fixed range and angle would be formed [19].

MOTIVATION

NUMERICAL SIMULATIONS

CONCLUSION