On the Synthesis of Full-Spectrum-Accessible Leaky-Wave Array Systems for Wideband Frequency-Scanning Radar Applications

For traditional frequency-scanning radars (FSRs), the range resolution is unavoidably worse than its expected value due to the inefficient use of the given signal spectrum. This issue, which intrinsically renders FSRs less competitive than typical frequency-modulated continuous-wave radars (FMCWRs), can be well tackled by employing the filter-bank leaky-wave antenna (FB-LWA) array system (as proposed in our previous work) to enable FSRs with full-spectrum-accessible capabilities. While the theoretical mapping relation between the FSR's characteristic system parameters and the FB-LWA array's design information is currently uncharted in communities (by contrast, a similar mapping relation is well known in FMCWRs), our work aims to fill such a gap by establishing a relevant synthesis theory for the FB-LWA array system. Notably, two critical issues related to the array synthesis are carefully addressed, namely (i) how FSRs can achieve the same range resolution as FMCWRs for a given signal bandwidth, and (ii) when FSRs can use fewer channels while sharing the same range resolution as FMCWRs. Additionally, to facilitate the synthesis of an FB-LWA array in practice, a streamlined three-step design flow is summarized, which is then followed by the modeling, simulation, and measurement of a four-element microstrip combline FB-LWA array for case studies and demonstration. It is shown that the synthesis theory presented in this work makes it straightforward to build an FB-LWA array once radar system parameters are determined, paving the way for the future deployment of full-spectrum-accessible FSRs.