Broadband high-gain circularly polarized microstrip antenna

A broadband high-gain circularly polarized microstrip antenna comprises a floor, a feed coaxial, a bottom dielectric substrate, a chamfered U-shaped slot microstrip, a top dielectric substrate, a substrate integrated waveguide square cavity, and a 2*2 microstrip radiation unit. The substrate integrated waveguide square cavity is composed of a bottom square microstrip line, a metal cylinder array,a top square microstrip line, and a part of the top dielectric substrate surrounded by the metal cylinder array. The respective parts of the antenna are stacked in order from bottom to top. The antenna can be achieved by a common double-layer microstrip printed board process or by an LTCC process. The method uses a form that a single-point feeding lower microstrip excites the upper 2*2 microstripradiation unit through the substrate integrated waveguide square cavity, increases the gain while realizing a wide frequency band, thereby avoiding the use of a complicated feed network. The circularpolarization of the antenna is achieved by means of chamfering on two rectangular microstrips. The antenna can be used as a single antenna or as a wide-angle scanning array antenna element.