Design For Ka-Band Couple Circular Polarization Feed Being Possessed Of Receive And Transmit

With the capacity demands of satellite communication channel increasing, as well as the businesses of C and Ku band becoming overcrowded day by day, L,C,X and Ku band etc. couldn't meet the high-speed, broadband, small aperture terminal and other applications. In recent years, an increasing number of countries and institutions have developed and used the Ka-band satellite communication systems. The feed is an important component of the antenna, and the performance of the feed directly affects the performance of the antenna.The Ka-band dual circular polarization feed with reception and transmission has been designed, which consists of four parts:a radiant horn, a coaxial partial-wave device, a circular polarizer of transmission band and a circular polarizer of reception band on the background of the application of the Luneburg lens antenna in this paper. The radiant horn applies the structure of the axial-groove corrugated horn with good symmetry, low sidelobe and broad band. The coaxial partial-wave device has been used to achieve the dual-frequency transmission and isolation of the transceiver signal in the method of internal and external waveguide nest. With the transmission high frequency signal fed by coaxial waveguide, circular polarization waves are formed through the septum polarizer, which are delivered into the inner waveguide of the coaxial waveguide and radiated out by the corrugated horn. The low frequency circularly polarized signals received by the corrugated horn transmitting through the internal and external waveguide of the coaxial partial-wave device are extracted out through the four orthogonal symmetric rectangular waveguide on the outer wall, form two-way orthogonal linear polarization signals through the magic T, and then are sent to the waveguide slot bridge to achieve reception of circular polarization signal.In this thesis, on the base of introducing the design theory of the each part of the feed system, the each part is respectively simulated and optimized by ANSOFT HFSS software using the finite element method. In the Ka reception band (19.7GHz-21.2GHz) and Ka transmission band (29.5GHz-31.0GHz), the dual circular polarization transceiver are achieved. The simulation results meet the expectations.