Filter-Bank-Enabled Leaky-Wave Antenna Array Technique for Full-Band-Locked Radar System in Stitched Frequency-Space Domain

TL;DR

This paper introduces a filter-bank-enabled leaky-wave antenna array technique to achieve full-band-locked radar systems with decoupled range and angle resolutions, demonstrated through modeling, fabrication, and measurements.

Contribution

It proposes a novel FB-enabled LWA array design for full-band-locked radar, providing analytical design conditions and a practical implementation approach.

Findings

Demonstrated frequency-space stitching behavior in simulations and measurements.

Achieved enhanced spectrum bandwidth and widened radiation beamwidth.

Validated the feasibility of the proposed array solution for decoupled resolution in FSR systems.

Abstract

Inspired by the filter-bank (FB) concept that is normally used for multi-rate signal processing, an FB-enabled array technique of leaky-wave antennas (LWAs) is proposed and studied for creating full-band-locked frequency-scanning radar (FSR) systems in a stitched frequency-space domain. This is mainly for addressing the coupling dilemma between the range and angle resolutions, which is historically and naturally inherited from a conventional FSR. First of all, the frequency-modulated continuous-wave system architecture is selected to exemplify and recall the characteristics of a conventional FSR with an emphasis on that resolution coupling. Then, a radar solution featuring a stitched frequency-space domain is introduced for the resolution decoupling, depending on an array of FB-enabled LWA channels. With the radar equation, FB-related conditions for realizing the critical frequency-space stitching are analytically derived and equivalently converted into several design specifications of an array of LWAs, i.e., engineered beam-scanning functions, beam-crossovers, and phase alignments. To facilitate the practical implementation of such an array technique, a detailed and generalized design flow is developed. Finally, for a simple proof of concept, an FB-enabled two-channel LWA array is modeled, fabricated, and measured. Simulated and measured results are in a reasonable agreement, and both demonstrate the desired frequency-space stitching behavior, i.e., enhanced spectrum bandwidth and widened radiation beamwidth. The proposed array solution may be potentially deployed for FSR systems with a full-band-locked beam illumination and a decoupled range-angle resolution, which may present a competitor against the phased array technique.