A Broadband Quad-Beam Patched Leaky-Wave Antenna Based on Substrate Integrated Coaxial Line for Multi-Beam Applications

In this letter, a novel broadband quad-beam frequency-scanning patched leaky-wave antenna (LWA) based on substrate integrated coaxial line (SICL) is proposed, analyzed and demonstrated. Firstly, the generation mechanism of four beams is introduced. Then, a broadband 2-way Tee power divider based on SICL technology is developed to feed a 1×2 antenna array, and good impedance matching from 20 to 45 GHz is achieved. Next, patch structures are loaded to antenna aperture to improve radiation performance of the antenna array. Measured results show that the peak gain value of the proposed quad-beam antenna is 9.32 dBi and the frequency beam scanning range for each beam is about 57°. Moreover, the -10 dB impedance bandwidth is from 21.42 to 31.65 GHz (38.7%). The antenna array has the characteristics of easy fabrication, broadband and quad-beam radiations, which provides a new design method for broadband wide-scanning-angle quad-beam LWA, and can meet the demand of multi-beam requirements in radar, space–air–ground–sea integrated network (SAGSIN) and other related fields.