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US 7,009,573 B2Granted
Compact bidirectional repeaters for wireless communication systems
AssigneeCalAmp Corp.
InventorsJames J. Hornsby, Gary G. Sanford, Kris Kelkar, Shawn Aleman, Vishwanaph G. Upadhye
Life of this patent
Estimating the term…
Abstract
Compact bidirectional repeaters are provided for wireless communication systems. Their compact size is realized with repeater structures that include different-polarization antennas, back lobe suppressing structures, circuit feedback paths, antenna-feedback detectors, and automatic gain control.
Claims47
A bidirectional repeater, comprising:
- a first antenna arranged to have a first polarization;
- a second antenna arranged to have a second polarization that differs from said first polarization by a polarization difference;
- a first amplifier circuit configured to receive a first signal from said first antenna and to provide an amplified first signal to said second antenna;
- and
- a second amplifier circuit configured to receive a second signal from said second antenna and to provide an amplified second signal to said first antenna;
- further including:
- a first choke arranged to reduce feedback signals from said first antenna to said second antenna;
- and
- a second choke arranged to reduce feedback signals from said second antenna to said first antenna;
- wherein:
- said first choke is arranged to form a shorted first cavity and define a slot that electromagnetically couples said first cavity to said first antenna;
- and
- said second choke is arranged to form a shorted second cavity and define a slot that electromagnetically couples said second cavity to said second antenna.
10 more elements
A bidirectional repeater, comprising:
- a first antenna arranged to have a first polarization;
- a second antenna arranged to have a second polarization that differs from said first polarization by a polarization difference;
- a first amplifier circuit configured to receive a first signal from said first antenna and to provide an amplified first signal to said second antenna;
- and
- a second amplifier circuit configured to receive a second signal from said second antenna and to provide an amplified second signal to said first antenna;
- further including:
- a first choke arranged to reduce feedback signals from said first antenna to said second antenna;
- and
- a second choke arranged to reduce feedback signals from said second antenna to said first antenna;
- wherein at least one of said first and second chokes comprises two chokes arranged on opposite sides of one of said first and second antennas.
7 more elements
A bidirectional repeater, comprising:
- a first antenna arranged to have a first polarization;
- a second antenna arranged to have a second polarization that differs from said first polarization by a polarization difference;
- a first amplifier circuit configured to receive a first signal from said first antenna and to provide an amplified first signal to said second antenna;
- and
- a second amplifier circuit configured to receive a second signal from said second antenna and to provide an amplified second signal to said first antenna;
- further including:
- a first feedback circuit that extracts a first sample signal from a portion of said first amplifier circuit and provides a first feedback signal to another portion of said first amplifier circuit that reduces feedback from said second antenna to said first antenna;
- and
- a second feedback circuit that extracts a second sample signal from a portion of said second amplifier circuit and provides a second feedback signal to another portion of said second amplifier circuit that reduces feedback from said first antenna to said second antenna.
6 more elements
A bidirectional repeater, comprising:
- first and second antennas;
- a first amplifier circuit configured to receive a first signal from said first antenna and to provide an amplified first signal to said second antenna;
- a second amplifier circuit configured to receive a second signal from said second antenna and to provide an amplified second signal to said first antenna;
- a first feedback circuit that extracts a first sample signal from a portion of said first amplifier circuit and provides a first feedback signal to another portion of said first amplifier circuit that reduces feedback from said second antenna to said first antenna;
- and
- a second feedback circuit that extracts a second sample signal from a portion of said second amplifier circuit and provides a second feedback signal to another portion of said second amplifier circuit that reduces feedback from said first antenna to said second antenna.
3 more elements
A bidirectional repeater, comprising:
- a first antenna arranged to have a first polarization;
- a second antenna arranged to have a second polarization that differs from said first polarization by a polarization difference;
- a first amplifier circuit that, with a first gain, amplifies a first signal from said first antenna to thereby provide an amplified first signal to said second antenna;
- a second amplifier circuit that, with a second gain, amplifies a second signal from said second antenna to thereby provide an amplified second signal to said first antenna;
- a detector that senses the presence of feedback between said first and second antennas;
- and
- a variable attenuator in at least one of said first and second amplifier circuits that responds to said detector and adjusts at least one of said first and second gains to eliminate said feedback.
4 more elements
A bidirectional repeater, comprising:
- a first antenna arranged to have a first polarization;
- a second antenna arranged to have a second polarization that differs from said first polarization by a polarization difference;
- a first amplifier circuit that, with a first gain, amplifies a first signal from said first antenna to thereby provide an amplified first signal to said second antenna;
- a second amplifier circuit that, with a second gain, amplifies a second signal from said second antenna to thereby provide an amplified second signal to said first antenna;
- a detector that senses the presence of feedback between said antennas;
- and
- a variable attenuator in at least one of said first and second amplifier circuits that responds to said detector and adjusts at least one of said first and second gains to reduce said feedback.
4 more elements
A bidirectional repeater, comprising:
- a first antenna arranged to have a first polarization;
- a second antenna arranged to have a second polarization that differs from said first polarization by a polarization difference;
- a first amplifier circuit configured to receive a first signal from said first antenna and to provide an amplified first signal to said second antenna;
- a second amplifier circuit configured to receive a second signal from said second antenna and to provide an amplified second signal to said first antenna;
- and
- at least one choke arranged to form a shorted cavity and define a slot that electromagnetically couples said cavity to one of said first and second antennas with said choke positioned to reduce feedback signals between said first and second antennas.
3 more elements
Dependencies are inferred from the claim text.