H-Plane Cross-Polarization Reduction of a Rectangular Patch Antenna Using SISL Technology

This letter proposes a simple rectangular patch antenna with reduced H-plane cross polarization using substrate integrated suspended line (SISL) technology. Compared with the conventional patch antenna, the embedded air cavities in the multilayer SISL provide a lower loss characteristic and higher gain. However, the SISL patch antenna is prone to high H-plane cross polarization. The nonradiating edges of the traditional patch are extended to the electric walls of the SISL to reduce the orthogonal E-fields of the nonradiating edge, which suppresses the H-plane cross polarization without affecting the copolarization. A slot is introduced to provide frequency tuning capabilities. The simulation and measurement results are well agreed. Measured results show a gain of about 9.85 dBi, and the H-plane cross polarization is less than -20.8 dB.