Circularly Polarized Leaky-wave Antenna Based on SubstrateIntegrated Waveguide Space Harmonic

A circularly polarized leaky-wave antenna (LWA) is implemented on the substrate integrated waveguide (SIW) based on space harmonic radiation. The LWA cuts the current in two different directions by opening a cross-shaped slot on the substrate integrated waveguide. It realizes circular polarization and frequency sweeping characteristics by adjusting parameters of the slot. The antenna achieves a sweep range of 36°~13° in the θ direction backward radiation by -1 space harmonic from 15GHz to 17GHz. The gain is basically above 13.5dB. Parameters of the cross-shaped slot on the antenna performance are studied. The antenna is fabricated and the measurement results are agree well with the simulation ones.