Compact broadband circularly polarized cross-dipole antenna with low-pass filtering response

The invention discloses a compact broadband circularly polarized cross dipole antenna with low-pass filtering response. The compact broadband circularly polarized cross dipole antenna comprises a top layer dielectric substrate, a middle layer dielectric substrate and a bottom layer dielectric substrate. The upper surface of the top dielectric substrate is printed with two pairs of vertical metal arms, a bent metal outer frame and four square metal inner frames of rectangular crossed dipoles for loading meandering flow, and the lower surface of the top dielectric substrate is printed with another two metal arms; the two rectangular dipole arms on the same surface are connected through a 1/4 printing circular ring of which the perimeter is the wavelength corresponding to the working frequency; a square metal patch is printed on the upper surface of the middle-layer dielectric substrate, four metal plates are loaded on four right angles of an air layer between the middle-layer dielectric substrate and the bottom