Compact multi-channel quasi-optical feed network and designing method thereof

The invention discloses a compact multi-channel quasi-optical feed network. The compact multi-channel quasi-optical feed network comprises a feed network upper layer and a feed network lower layer. The feed network lower layer comprises a plurality of ellipsoid reflectors, a spatial filter, a plane mirror and a periscope. The feed network upper layer comprises a plane mirror, a plurality of ellipsoid reflectors and a periscope. The feed network upper layer and the feed network lower layer share one ellipsoid reflector and two hyperboloid reflectors. The two hyperboloid reflectors reflect scattering signals converged by the ellipsoid reflector and change the height of a beam transmission axis. Multi-channel transmission is carried out through the spatial filter, part of channel beams are reflected back to the feed network upper layer through the periscopes, separated multi-channel signals are arranged in a layering mode, and multi-channel signals are reflected back through the plane mirrors and the ellipsoid reflectors and are converged to be fed back to corresponding feed source horns. The compact multi-channel quasi-optical feed network is simple in structure and compact in layout, the problem of limited space of a satellite-borne radiometer antenna feed system is solved, and the requirement for designing the antenna feed system shared focus and shared optical axis of a multi-channel satellite-borne radiometer is met.