Abstract: An element which acts as an antenna and circular-polarizer for the domestic reception of DBS signals has a front plate of aluminum alloy, with two slots and of differing length and orthogonally crossing at their midpoints. The width and length of slots and are chosen in order to provide equal power flow through the slots and adequate bandwidth appropriate to the format of the DBS frequency band.Behind the plate the element has a rectangular housing to form a cavity containing a suspended strip line with a support whose free end is located below the point of crossing the two slots, and which extends outwardly therefrom in a straight line bisecting the angle formed by adjacent arms of the slots and being in a plane parallel to the plate.

Abstract: An antenna is formed of four arrays each having sixteen helical antenna elements with probes located within a common resonant cavity. Thus cavity is used to combine all the outputs of elements.The elements of array are arranged over the surface of box such that the probes are located at the voltage antinodes of the resonance field patterns in order to maximize the coupling efficiency. Likewise the output probe for each cavity 6 is also located at a voltage antinode; output probe enables the signal combined in cavity to pass into a waveguide, also connected to other arrays and, for passage to the television receiver.