Research On Semi-enclosed Patch Antenna And High-performance Sputter Plate Feed

In recent years,the research on microstrip antennas with small size,low cost and cross-polarization has become the mainstream of microstrq antenna.However,a disadvantage of microstrip antennas is the poor cross-polarization.Therefore,the research on microstrip antennas with low cross-polarization is of great significance.For parabolic antennas,the support that holds the feed obscures the primary reflector and reduces the antenna's radiation efficiency.The research on the high performance splash-plate is of great significance.The content of this work is summarized as follows:(1)A semi-closed patch antenna(SCP antenna)is proposed.Two rows of uniform shorting-pins are connected with non-radiating edge and the GND of the antenna so that antenna boundary conditions are changed:the magnetic walls are placed on the radiating-edges,and the electrical walls are placed on the non-radiating edges.The shorting-pins and patch and the GND are connected to form a semi-closed electric wall cavity.Based on the cavity model theory,the far-field pattern of non-radiative edge radiation is calculated,and results show that the contribution of non-radiating edge radiation to cross-polarization of E-plane and H-plane is zero.The first higher mode TM02 is calculated and proved to be the major contributor to the H-plane cross-polarization.Simulation and test results show that the semi-closed patch can effectively suppress the cross-polarization of the H-plane of the microstrip antenna,and the cross-polarization of the H-plane of patch antenna is reduced to-3 4dB?(2)A high performance splash-plate feed is designed.The dielectric rod connects the circular waveguide and the sub-reflective surface,and the matching of the feed is achieved by adjusting the height and radius of each dielectric table in the circular waveguide.Through the simulation analysis,the feed is proved to be with a rotationally symmetrical pattern and a good matching,which demonstrates that feed design is reasonable.The VSWR is less than 1.1 in the bandwidth of 10.50GHz?11.53GHz.The antenna system achieves that the VSWR is less than 1.1 in a bandwidth of 10.50GHz?11.43GHz.The antenna system is of a rotationally symmetric pattern,a high gain,a very low return loss and little processing difficulty.Therefore,it can serve as a theoretical assumption for engineering.