Dual-band and dual-polarization millimeter wave feed source

The invention provides a dual-band and dual-polarization millimeter wave feed source which comprises a radiation end, a Ka-band orthogonal mode coupling and a W-band orthogonal mode coupling. The radiation end and the couplings use a waveguide structure. Dual bands and dual polarization are realized through single caliber. A high band is located in the middle. Low bands carry out feeding from sides. A high-band dual-mode feed source is connected with an external orthogonal mode coupling. The low bands carry out feeding from a circular waveguide segment with increasing diameter. The dual-polarization feed source has a simple main structure, and breaks through the technical problems of the dual-band and dual-polarization millimeter wave feed source. In order to prevent crosstalk and improve the feed source performance, a filter is added on an output rectangular waveguide segment of a low-band orthogonal mode coupling. The filter is a low-pass filter which has low-band passband and high-band stop-band. Two kinds of polarization exit waveguide of two bands are respectively located in four directions of a major radiation waveguide axis, are in pairwise orthogonal, are staggered up and down, are not located in the same level, and are easily connected with rear end waveguide.