  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.
