Application of Doppler beam sharpening for azimuth refinement in prospective low‐THz automotive radars

Abstract

In this study, the authors investigate the application of the Doppler beam sharpening (DBS) technique for angular refinement to the emerging area of low-terahertz (THz) radar sensing. Ultimately this is to improve radar image quality in the azimuth plane to complement the excellent range resolution and thus improve object classification in low-THz radar imaging systems for autonomous platforms. The study explains the fundamental theory behind the process of DBS and describes the applicability of DBS to automotive sensing, indicating the potential for synthetic beamwidths of a fraction of a degree. Low-THz DBS was experimentally tested under controlled laboratory conditions, not only to accurately localised target objects in Cartesian space but also to provide unique object imaging at low-THz frequencies with wide azimuthal beamwidth antennas. It was shown that a stationary (i.e. non-scanned) wide beam antenna mounted on a moving platform can deliver imagery at least comparable to that produced by physical beamforming, be that steering arrays or narrow beam scanning antennas as in the experimental case presented.

Space-Based Sub-THz ISAR for Space Situational Awareness—Concept and Design

“…The choice of a frequency of around 300 GHz has been discussed above. This also allows a signal bandwidth of 20 GHz to be readily achieved [10], giving a range resolution of about 1 cm.…”

A Review of Broadband Low-Cost and High-Gain Low-Terahertz Antennas for Wireless Communications Applications

“…What's more, imaging with higher resolution [8]- [11] can also be achieved by increasing the frequencies and bandwidth of incident waves. With this function, THz imaging is rapidly developed to meet the requirement of some commercial applications, such as THz medical imaging test [12]- [14], atmospheric and environmental monitoring [15]- [17], THz radar [18], [19], national security and anti-terrorism [20]- [23].…”

Simulation of air‐to‐ground ranging mode of airborne monopulse radar over complex terrain

“…Advances in multifunction radar systems have led to airborne radar systems exhibiting superior capabilities for various modes such as the target track mode, auto‐acquisition mode, and air‐to‐ground mode [1]. Among various modes, the air‐to‐ground mode is important since it supports various ground missions, including ground moving target indication/tracking [2, 3], Doppler beam sharpening [4, 5], and air‐to‐ground ranging (AGR). In engagement environments, AGR is especially crucial for missile and bomb guidance.…”