Abstract: There is disclosed herein an antenna, particularly for use at high frequencies such as approximately one gigahertz and above, which is frequency selective. The antenna design allows signals at a given frequency to be preferentially received, as distinguished from broadband reception. The antenna design can be modified for reception of signals of different given frequencies. The antenna comprises a plurality of parabolic sections in the form of concentric rings or segments with each segment being offset axially from the next adjoining segment to thereby provide an antenna which is relatively flat, or having a low profile, as compared to a standard parabolic antenna. The surface of each segment is a segment of a different focal length parabola, but with each parabolic surface being a function of the signal wavelength (or frequency) to be received by the antenna. The antenna may be round, rectangular or have other shapes. Also disclosed are feed and pick-up arrangements for the antenna.

Abstract: There is disclosed herein a television system wherein television signals are scrambled or otherwise encoded at the transmitting facility and then unscrambled or decoded at the receiving facility, typically a home television subscriber. The television signals have a number of video fields inverted as transmitted, and these fields are reinverted by the home decoder. The normal sync pulses of a television signal are replaced with burst flags coded in the video portion of the signal. The decoder senses these burst flags and recreates conventional sync so that a composite video signal can be provided to the television receiver. The system includes a relatively simple string of decade counters and associated logic for determining which video fields are to be reinverted. The decoder is switchable, as with a suitable card or switches, to set the same for properly decoding the video.