Abstract: A ground shield is connected to a princted circuit board or antenna card in an antenna unit cell to cover a balun to prevent or inhibit the ability of a differential signal flowing towards or through the balun from coupling with a similar differential signal flowing through an adjacent antenna card in the antenna unit cell. This ground shield may be one of a pair of ground shields on the antenna card. Two ground shield can be positioned on opposing sides of the balun to enhance isolation thereof by shielding the differential signals flowing towards and through the balun from coupling with adjacent differential signals to thereby increase bandwidth performance of the antenna unit cell. The ground shields may be generally or substantially or totally planar so as to be conformal with a substrate or dielectric layer of the antenna card or printed circuit board.

Abstract: A cone antenna has at least one resistor electrically coupled to the radiating structure of the cone antenna. The capacitor may be part of a resistor network that is electrically connected to the cone. One or more patches may be coupled to the resistor network which act as a capacitor. A feed card may be embedded within a ground plane to enable the exterior of an antenna assembly to be conformal with an outer surface of a platform carrying the cone antenna.

Abstract: An array antenna has a plurality of antenna unit cells arranged in rows and columns, or in another configuration. Each unit cell from the plurality of unit cells includes a circularly polarized radiator and a balun. The array antenna further includes a reactive element or a circuit element (such as a capacitor or resistor or even an inductor) on the circularly polarized radiator that is coupled an adjacent unit cell in one of the row and the column. A spacing distance between adjacent unit cells coupled via the circuit element that is at most half of a wavelength at a frequency maximum of the array antenna, wherein the spacing distance reduces likelihood of grating lobes.

Abstract: An array antenna has a plurality of antenna unit cells arranged in rows and columns, or in another configuration. Each unit cell from the plurality of unit cells includes a circularly polarized radiator and a balun. The array antenna further includes a reactive element or a circuit element (such as a capacitor or resistor or even an inductor) on the circularly polarized radiator that is coupled an adjacent unit cell in one of the row and the column. A spacing distance between adjacent unit cells coupled via the circuit element that is at most half of a wavelength at a frequency maximum of the array antenna, wherein the spacing distance reduces likelihood of grating lobes.