Ka-frequency-band broadband circularly-polarized four-port microwave network

The invention discloses a Ka-frequency-band broadband circularly-polarized four-port microwave network. The Ka-frequency-band broadband circularly-polarized four-port microwave network may simultaneously transmit and receive circularly-polarized signals at a Ka-band reflector antenna, and mainly achieves combination of the circularly-polarized signals and high isolation degree of signal transmission and reception. The Ka-frequency-band broadband circularly-polarized four-port microwave network comprises two frequency duplexers, a low-frequency waveguide bridge, a high-frequency waveguide bridge, and a Ka broadband orthogonal-mode coupler. Each of the two waveguide outlets of the Ka broadband orthogonal-mode coupler is connected with the corresponding frequency duplexer. The through ports of the two frequency duplexers are communicated with the two waveguide ports of the low-frequency waveguide bridge one to one. The outlets of the sidewall branches of the two frequency duplexers are communicated with the two waveguide ports of the high-frequency waveguide bridge one to one. The Ka-frequency-band broadband circularly-polarized four-port microwave network has excellent characteristics of ultra wide band, high isolation degree, low loss, low standing-wave ratio, and large power capacity, may satisfy a requirement of all Ka satellite communication transmit-receive common circularly-polarized antennas for microwave network design, and has high application value.