RCS of a Microstrip Leaky-Wave Antenna

The monostatic radar cross section (RCS) of a microstrip leaky-wave antenna (MLWA) is investigated. Both full-wave simulation and laboratory measurement are carried out to characterize its RCS as a function of frequency and aspect angle. Three distinct scattering features in the range-aspect plane are observed. By modeling the scattering mechanisms individually, the observed features can be clearly identified as the primary antenna mode scattering, higher-order bounce antenna mode scattering and structural mode scattering. The unique range-extended return due the antenna mode scattering is further interpreted using a time-of-arrival ray picture. It is shown that the extended range delay is directly attributable to the continuous aperture of the MLWA and the frequency-dependent group velocity of the leaky wave.