A dual polarized aperture coupled microstrip antenna with active switching

This paper introduces a dual polarized aperture coupled microstrip antenna that uses active switching. The microstrip antenna has a good front-to-back ratio, high port-to-port isolation, high copolarisation-crosspolarisation isolation, and nominal gain. The switching circuit uses relatively inexpensive parts that are integrated on the same substrate as the antenna feed network. The antenna´s aperture is cross-shaped. The patch size, aperture, and feed lines are tuned for optimal performance for 100 ohms impedance at an operating frequency of 16 GHz. The simulated copolarisation-crosspolarisation isolation is better than 20 dB across ± 90° in both the E and H planes. The simulated bandwidth is 7.5%; port isolation is better than -30 dB; and the front to back ratio is nominally 12 dB.