Multi‐beam SIW leaky‐wave antenna with 2‐D beam scanning capability for millimeter‐wave radar applications.

In this article, a multi‐beam substrate integrated waveguide (SIW) leaky‐wave antenna (LWA) is proposed for millimeter‐wave radar applications, which owns the advantages of 2‐D scanning capability, high gain, low profile, and single layer configuration. The proposed antenna consists of a beam‐forming network (BFN) based on a 2‐D SIW parabolic reflector with eight waveguide feedings, and a 16‐element LWA array. The open‐stopband of the LWA is suppressed by employing a longitudinal slot into a conventional transverse slot LWA unit. In the E‐plane, the BFN can generate eight desired distributions of the amplitude and the phase gradients which steers beam from −17.3° to 30.8° with the crossover level higher than −5.22 dB. In the H‐plane, the frequency scanning LWA array can offer a continuous beam scanning range from −23° to 19° with operating frequency from 21 to 29 GHz. Finally, the antenna is prototyped and experimentally verified. The measured results are in accord with the simulated ones. The characteristics of the proposed antenna make it a very promising solution for applications in low‐cost millimeter‐wave radar systems. [ABSTRACT FROM AUTHOR]