Tunnel distributed cable antenna system with signal top coupling approximately same radiated energy
First Claim
1. A system for providing radio communication to and from a transceiver in a confined region into which external radio signals do not penetrate, said system comprising:
- (a) first and second elongated low loss coaxial cable segments in said region,(b) means for applying radio frequency signals to one end of said first cable segment,(c) a plurality of transmitting antennas proximate to said first cable segment at spaced intervals therealong,(d) a plurality of signal tap means coupling each of said transmitting antennas to said first cable segment, each tap means having the function of extracting a preselected amount of radio frequency energy from said first cable segment and for feeding such preselected amount of energy to the transmitting antenna with which it is associated so that the energy radiated from each transmitting antenna is approximately the same,(e) a plurality of receiving antennas proximate to said second cable segment at spaced intervals therealong,(f) means for receiving radio frequency signals from one end of said second cable segment,(g) a plurality of signal tap means coupling each of said receiving antennas to said second cable segment, each tap means having the function of feeding a preselected amount of radio frequency energy to said second cable segment from the receiving antenna with which it is associated so that the total attenuation of signals received by each of said receiving antennas from said antennas to said one end of said second cable segment is approximately the same.
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Accused Products
Abstract
A distributed radio antenna system for extending radio communications into confined regions into which external radio signals do not penetrate, the system having separate transmitting (TX) and receiving (Rx) antenna systems. Each Tx or Rx system has an elongated low loss coaxial cable system (18 or 31) and a plurality of antennas (23 or 28) connected to each of the individual segments of the cable system at spaced distances along the length of the cable segment. The antennas are coupled to the cable segments by signal taps (21 or 21'"'"') having adjustable or preselected values of attenuation so that the power fed to each TX antenna (23) from the Tx cable system (18) is approximately the same and so that the attenuation of the signals received from each Rx antenna (28) is approximately the same, thereby conserving power and reducing system cost. The Rx antennas (28) are located generally intermediate to the Tx antennas (23) so that spurious and intermodulation signals are substantially diminished by space attenuation.
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Citations
13 Claims
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1. A system for providing radio communication to and from a transceiver in a confined region into which external radio signals do not penetrate, said system comprising:
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(a) first and second elongated low loss coaxial cable segments in said region, (b) means for applying radio frequency signals to one end of said first cable segment, (c) a plurality of transmitting antennas proximate to said first cable segment at spaced intervals therealong, (d) a plurality of signal tap means coupling each of said transmitting antennas to said first cable segment, each tap means having the function of extracting a preselected amount of radio frequency energy from said first cable segment and for feeding such preselected amount of energy to the transmitting antenna with which it is associated so that the energy radiated from each transmitting antenna is approximately the same, (e) a plurality of receiving antennas proximate to said second cable segment at spaced intervals therealong, (f) means for receiving radio frequency signals from one end of said second cable segment, (g) a plurality of signal tap means coupling each of said receiving antennas to said second cable segment, each tap means having the function of feeding a preselected amount of radio frequency energy to said second cable segment from the receiving antenna with which it is associated so that the total attenuation of signals received by each of said receiving antennas from said antennas to said one end of said second cable segment is approximately the same. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 13)
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11. A signal tap for use with a coaxial cable having an outer metallic shield and a center metal conductor, said cable having a hole extending through said metallic shield and exposing said center conductor, said signal tap comprising:
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a metal clamp having a threaded hole therethrough, said clamp being adapted to surround and grip said cable with the threaded hole in said clamp being adjacent said hole in said cable, a threaded metal tube threadably receivable in said clamp hole, a coaxial connector at one end of said tube, a series-connected resistor and capacitor in said metal tube with one end thereof connected to said coaxial connector, said capacitor having a low impedance to radio frequencies and said resistor having a selected value of resistance to enable a selected amount of radio frequency energy to be coupled to or from said coaxial cable, means on the other end of said series-connected resistor and capacitor for electrically engaging said center conductor of said cable when said clamp surrounds and grips said cable and said threaded tube is threaded into said hole of said clamp. - View Dependent Claims (12)
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Specification