Satellite broadcast signal receiving system

• US 4,509,198 A
• Filed: 09/22/1982
• Issued: 04/02/1985
• Est. Priority Date: 10/19/1981
• Status: Expired due to Term

• Current Assignee: DX Antenna Co., Ltd. (Elecom Co., Ltd.)
• Original Assignee: DX Antenna Co., Ltd. (Elecom Co., Ltd.)
• Inventors: Nagatomi, Akihiko
• Primary Examiner(s): Bookbinder, Marc E.
• Application Number:
  US06/421,083
• Time in Patent Office: 923 Days
• Field of Search: 455/3, 455/4, 455/6, 455/189, 455/190, 455/275, 455/131, 358/86, 358/83
• US Class Current: 725/68
• CPC Class Codes: H01Q 21/30 Combinations of separate antenna units operating in different wavebands and connected to a common feeder system
• CPC Class Codes: H03J 5/242 used exclusively for band selection
• CPC Class Codes: H04B 1/18 Input circuits, e.g. for coupling to an antenna or a transmission line coupling networks between antennas or lines and receivers independent of the nature of the receiver H03H
• CPC Class Codes: H04N 7/20 Adaptations for transmission via a GHz frequency band, e.g. via satellite

Abstract

A satellite broadcast signal receiving system for receiving a plurality of signals of individual transmission bands, which are mutually different in frequency and/or polarization angle, transmitted through an artificial satellite, wherein the signals picked up by an antenna or antennas are first applied to a plurality of outdoor units each corresponding to one transmission band and comprising a convertor for converting the incoming signal into an IF signal, and the converted IF signals are then applied through a change-over switch to a common indoor unit including a demodulator to be demodulated for application to a conventional television set or the like.

Claims

1. A broadcast signal receiving system comprising a plurality of outdoor receiving units for receiving a plurality of broadcast signals, and converting them into intermediate frequency signals in a common frequency band, an indoor unit having an input for receiving said intermediate frequency signals from a selected one of said outdoor units, switching means, a plurality of coaxial cables each coupling a respective outdoor unit to said switching means, means for connecting the input of said indoor unit to said switching means, said switching means selectively coupling one of said outdoor units through its associated coaxial cable to the input of said indoor unit via said connecting means, a power supply coupled to the switching means for supplying operating power to said one outdoor unit through the associated coaxial cable, said switching means including conduction path means coupled through said coaxial cables to said outdoor units to supply said operating power thereto through the associated coaxial cables and additional conduction path means for feeding respective ones of said intermediate frequency signals from the associated outdoor units to said indoor unit through said coaxial cables and connecting means, said switching means selectively applying operating power to said one of said plurality of outdoor units, which selective power application enables a respective one of said additional conduction path means to close in order to feed said selected, respective intermediate frequency signal from the selectively powered outdoor unit to said indoor unit.

2. A broadcast signal receiving system according to claim 1 wherein said switching means includes a common capacitor in series with the input to said indoor unit, a plurality of series connected diode/capacitor pairs with each series connected diode/capacitor pair connected between said common capacitor and a respective coaxial cable connected to an associated outdoor unit whereby each diode is positioned in series relationship between two capacitors, a switch including means for applying operating power through at least one inductor via said switch to a selected outdoor unit through the coaxial cable associated therewith and means including at least two frequency isolating inductors for producing a current flow through the diode associated with the selected outdoor unit to effect transmission of the respective intermediate frequency signals from the selected outdoor unit to the indoor unit.

3. A broadcast signal receiving system according to claim 2 wherein said switching means includes a common capacitor in series with the input to said indoor unit, a respective signal current control means associated with each outdoor unit including signal current control means having two terminals and open and closed positions, each of said relay means having one terminal connected to said common capacitor, a series connected capacitor connecting the other terminal of said current control means to the coaxial cable associated with a respective one of said outdoor units, a respective current conducting means having a pair of terminals associated with each current control means to close its respective current control means when current flow therethrough, one terminal of each current conducting means being connected through an inductor to the coaxial cable of the associated outdoor unit, said switching means applying an operating current to the other terminal of a current conducting means for energizing the associated outdoor unit and placing the associated signal current control means in said closed position to feed said selected, respective intermediate frequency signals from the selected outdoor unit to said indoor unit.