Research Ku-band Dual-polarized Microstrip Antenna

In this paper, a wideband dual-polarized microstrip array antenna at Ku-band was studied including the technology of microstrip antenna wideband and dual-polarized. Using the method of add the parasitic patch and air cavities to improve bandwidth.The relative impedance bandwidth of antenna element’s two ports were increased from1.7%and2.6%to16%and25.3%. A hybrid feed which uses microstrip line feeding and aperture coupled feeding was adopted to realize dual-polarized. The two feed networks were placed both sides of the ground plane, so it can improve the isolation of two ports. Aperture coupled feed method was mainly studied. The antenna element adopted H-shaped coupling slot which can be improve coupling, extend wideband and suppress cross-polarization well.Analysing and simulating the antenna element and array. The main dimensions of the antenna element were studied and I obtained the influence of the parameters on resonance characteristics. Based on the former design, I designed fort-elements and sixteen-elements square array with amplitude-phase feed. The relative impedance bandwidths of the sixteen-elements microstrip array are15.2%and14.7%when VSWR is less than2. The isolation between two ports is better than30dB and cross-polarization level is below-21.16dB.The maximum gain of two polarization ports are21.27dB and21.18dB. In order to suppress cross-polarization of two ports, a sixteen-elements microstrip array which adopted anti-phase feeding was developed. The isolation between two ports is better than33dB and cross-polarization level is below-28.7dB.