Wideband Dual-Polarized Low-Profile Filtering Microstrip Patch Antenna

A wideband low-profile dual-polarized filtering antenna is designed and simulated. It is realized using second-order bandpass filters with an air-cavity backed microstrip patch antenna functioning as the radiating resonator element. The single-layer planar design allows for realistic implementation in high throughput and wideband mobile handsets/base-station systems and agile radar transceivers. The dual-polarized antenna has fractional bandwidth 13.5%, peak broadside realized gain of 5.36dBi at operation frequency $f_{0}=4.8\mathbf{GHz}$, and provides at least 25dB of out-of-band gain suppression up to $2f_{0}$. The isolation between the two ports is at least 12dB in the passband region, with cross-pol discrimination greater than 16.5dB.