Abstract: An antenna/downconverter directed to the subscription television distribution industry having low cross polarization and broad bandwidth. The antenna/downconverter includes a director mounted to a housing which defines a reflector cup, side lobe suppression rim and a housing defining a chamber which provides environmental protection for downconverter electronics. Received microwave energy is coupled to the downconverter electronics from a point radially inward from the perimeter of a first receive disc axially spaced within the reflector cup using a probe surrounded by a conductive probe shield integral to the reflector cup. A second receive disc having a different radius than the first receive disc and axially spaced within the reflector cup is parasitically coupled to the first probe. The second receive disc additionally includes wings coupled to the perimeter of the reflector cup for shunting cross-polarized microwave signals.

Abstract: An decryption system which facilitates simultaneous decryption of multiple encrypted television channel signals thus making them simultaneously available for direct tuning in television receivers. The system is characterized by the utilization of a plurality of channel signals time synchronized with respect to a common timing reference signal. Each channel signal is encrypted in accordance with a predetermined encoding rule and distributed to subscriber sites where an unencrypted block of channel signals are made simultaneously available by decrypting them synchronously with the recovered timing reference signal in accordance with the inverse of the encoding rule. An interdiction apparatus then selectively jams a plurality of television channels from within the unencrypted block of channel signals thus making it possible for a provider to programmably interdict reception of selective channels by unauthorized subscribers.

Abstract: An antenna suitable for use at subscriber sites in a television distribution system having a high front-to-back ratio and optimized for reception within multiple frequency bands. The antenna is comprised of multiple tapered antenna stages including a primary antenna stage for receiving a primary frequency band and a coupling antenna stage for matching the impedance of the primary antenna stage to either a coaxial cable or downconverter electronics. The multiple antenna stages are alternatively formed from either a stamping of a metal sheet or a double sided printed circuit board.

Abstract: An encryption/decryption system which facilitates simultaneous decryption of multiple encrypted television signals thus making them simultaneously available for direct tuning in television receivers. The system is characterized by the utilization of a plurality of channel signals each containing picture portions and synchronization portions respectively corresponding to the picture components and synchronization components of a different video signal. Corresponding portions of all channel signals are time synchronized with respect to a common timing reference signal. Each channel signal is encrypted in accordance with a predetermined encoding rule and distributed to subscriber sites where the channel signals are made simultaneously available for viewing by decrypting them synchronously with the recovered timing reference signal in accordance with the inverse of the encoding rule.

Abstract: An antenna/downconverter directed to the subscription television distribution industry. The antenna/downconverter (20) includes an integral multidisc director mounted to a housing (51) which defines a reflector cup (54), side lobe suppression ears (38) and a chamber (66) which provides environmental protection for downconverter electronics (184). Received microwave energy is coupled to the downconverter electronics from the perimeter of a receive disc (50) axially spaced from the reflector cup. The housing defines a plurality of jaws (36) which facilitate alignment to variously polarized microwave signals when an installer receives a mounting mast in a selected one of the jaws.

Abstract: A structure (20) coupling a microwave signal to a waveguide (30) is provided. Transmission walls (26) are supported in the waveguide to only partially surround a probe (22) extending longitudinally from the waveguide wall. The probe preferably terminates at one end in a transmit/receive portion (36) directed into the waveguide internal space and at the other end in a launch portion extending through either the waveguide endwall (24) or sidewall (28). The structure is particularly suited for economical fabrication.

Abstract: A microwave filter (30) and method of fabrication in which an integral housing (22) defining a cavity (23) is formed from a blank (20) cut from a conductive sheet. The blank is bent to form the housing. The resultant housing includes resonators, resonator taps, tuning holes and tap apertures. Capacitance tabs and coupling tabs are added to the housing for tuning of the filter. The tabs are adjusted by access through the tuning holes in the blank. The blank further defines stops which align the taps with lines of a microstrip circuit when the filter is installed therein and grounding tabs for grounding to the microstrip ground plane. The filter may be in combline or interdigital configuration.

Abstract: A feed structure (24) is disclosed which facilitates reception of orthogonal linearly polarized signals from communication satellites. The structure includes probes (34, 36) combined in a cavity (28) with transmission members (50, 52) and an isolation member (54). The structure is particularly suited to enhance high signal to noise ratios because of short path lengths to external receiver circuits and to enable realization in simple economical one piece castings. The teachings of the invention are shown extended to dual band feed structures (124).