Range-dependent beamforming using element level waveform diversity

TLDR

Conventional phased arrays steer beams by applying a linear phase progression across the aperture, fixing the scan angle in the far field and causing the beam to point broadside when no phase progression is used. The authors propose a method to focus an antenna beam pattern as a function of range. The study demonstrates that adding a linear frequency shift across elements produces a range‑dependent scan angle in the far field.

Abstract

This paper presents a novel concept for focusing an antenna beam pattern as a function of range. In conventional phased arrays, beam steering is achieved by applying a linear phase progression across the aperture. Without this phase progression, the antenna beam points to broadside. However, a linear phase progression causes the electric field from each element to constructively sum in the far-field in a direction off broadside, resulting in an electronic scan. For a given linear phase progression, this scan remains fixed for all ranges in the far field. This paper shows that by applying an additional linear frequency shift across the elements, a new term is generated which results in a scan angle that varies with range in the far-field.