The invention relates to a four-band multi-polarization co-aperture feed source. The four-band multi-polarization co-aperture feed source is formed by combining a double
linear polarization antenna of a
Ku band and a double
circular polarization antenna of a
Ka band and comprises a conical horn, a Ku
circular waveguide, a tuning screw, a Ku
flange, a horizontal polarization power divider, a first
flange, a vertical polarization power divider, a medium rod, a
circular waveguide feed window, a stop screw, a transition section and a double
circular polarization antenna. The antenna of the
Ku band uses four ports for symmetrical feeding to improve the symmetrical characteristic of a directional diagram, a transmission
waveguide of an
electromagnetic field of the
Ku band is used as the transition section of the
electromagnetic field of the
Ka band, and the
resonance medium rod is embedded into the
waveguide of the Ku band for transmitting electromagnetic
waves of the
Ka band so that compactness of the antenna is greatly improved. By means of
dielectric waveguides and conical horn nesting technologies, the purposes of achieving antenna beam conformity and sharing one
phase center are achieved, uniformities of directional diagrams and uniformities of the phase centers in four working bands are guaranteed, isolation among bands is increased, and the compactness of the antenna is improved.