Miniature, flush mounted, microwave dual band cavity backed slot antenna

Claim 1

A miniature, flush mounted, microwave dual band antenna comprising: (a) an antenna body of a conductive material having an approximately Y-shaped cavity with a central vane and having an input port at the base of said Y-shaped cavity; (b) a block of a dielectric material having a central hole, said block being situated in the leg of said Y-shaped cavity with said central hole aligned with said input port; (c) a probe situated within said hole in said block and electrically insulated from said central vane, said probe having a central hole aligned with said input port into which the center conductor of a coaxial rf transmission line is inserted to excite said probe so that when said probe is excited said antenna resonates a lower frequency band energy primarily in the open non-dielectric spaces of said cavity, and resonates a higher frequency band energy primarily in the dielectric space of said block; (d) an aperture plate having a slot enclosing the open end of said cavity, the configuration of said slot being a function of the desired polarization of the energy radiated in the lower frequency band; (e) a dielectric window which covers said slot; and (f) a cover having an opening to accommodate said dielectric window which is attached to said antenna body to hold said dielectric window and said aperture plate in place.