Duplexer for simultaneous transmit and receive radar systems
First Claim
1. A method for simultaneously transmitting and receiving signals to and from an antenna of a radar system comprising the steps of:
- feeding a main transmit signal to the antenna through a circulator;
feeding return signals from the antenna through the circulator to a first high dynamic range (HDR) amplifier;
sampling a portion of the transmit signal;
amplifying said sampled signal portion with a second HDR amplifier;
modifying said sampled signal portion by adjusting the gain and phase of the second HDR amplifier; and
combining the modified sampled signal portion with the amplified signal from the first HDR amplifier to cancel leakage signals generated by the radar system.
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Accused Products
Abstract
An enhanced duplexer (1) which includes a combination of high dynamic range (HDR) amplifiers (11, 17) and a naovel signal cancellation circuit topology (15). Return signals from the circulator (3) are fed into the first HDR amplifier (11). A portion of the transmit signal is sampled with a directional coupler (7) and amplified with a second HDR amplifier (17) and then combined with the output of the first HDR amplifier (11) using a second directional coupler (13). The gain and phase of the second io amplifier (17) are adjusted so the leakage signals are canceled (19, 21) to enable a radar system to simultaneously transmit and receive signals to and from an antenna with increased sensitivity of operation.
53 Citations
16 Claims
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1. A method for simultaneously transmitting and receiving signals to and from an antenna of a radar system comprising the steps of:
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feeding a main transmit signal to the antenna through a circulator; feeding return signals from the antenna through the circulator to a first high dynamic range (HDR) amplifier; sampling a portion of the transmit signal; amplifying said sampled signal portion with a second HDR amplifier; modifying said sampled signal portion by adjusting the gain and phase of the second HDR amplifier; and combining the modified sampled signal portion with the amplified signal from the first HDR amplifier to cancel leakage signals generated by the radar system. - View Dependent Claims (2, 3, 4, 5)
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6. A method for operating a duplexer comprising the steps of:
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feeding a main transmit signal into a circulator which separates said signal into a transmit signal and a receive signal; obtaining return signals from the circulator and feeding said return signals to a first high dynamic range (HDR) amplifier; sampling a portion of a transmit signal and amplifying said signal with a second high dynamic range amplifier and combining said transmit signal with the output of the first HDR amplifier; providing the first and second HDR amplifiers to have phase and gain characteristics that mutually track each other; and adjusting the gain of the second HDR amplifier so that leakage signals are canceled or minimized to acceptable performance levels. - View Dependent Claims (7, 8)
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9. An enhanced duplexer enabling an antenna to simultaneously transmit and receive a signal, said duplexer comprising:
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a circulator communicating with a transmit feed path and a receive path, said receive path containing a first HDR amplifier; a cancellation circuit operatively connected between the transmit path and receiver path of the circulator for canceling leakage signals;
said cancellation circuit including;a second HDR amplifier for receiving return signals from the circulator; a first coupler connected to the output of the first HDR amplifier; a second coupler connected between the transmit path and the circulator for sampling a portion of a transmit signal; said second HDR amplifier operatively coupled between the first and second couplers; and a phase and gain trim circuit for adjusting the gain and phase of the second HDR amplifier to cancel the leakage signals. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16)
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Specification