초록 ▼

A leakage calibration and removal system and method estimates the complex in-phase and quadrature phase (I/Q) components of a leakage signal for each beam location in the sampled down-converted radar signal in a radar system (10). In a digital embodiment, the stored leakage calibration signal (264)

A leakage calibration and removal system and method estimates the complex in-phase and quadrature phase (I/Q) components of a leakage signal for each beam location in the sampled down-converted radar signal in a radar system (10). In a digital embodiment, the stored leakage calibration signal (264) is subtracted (206) from the sampled radar signal, and the resultant signal is processed (208, 210, 212) to detect targets. A leakage calibration process (250) is activated if a leakage signal test (214) indicates a problem for a sufficient number of consecutive scans (216), wherein for each beam location, M consecutive I/Q waveforms are averaged (252), known targets are removed (254, 256, 258), and the resulting signal is scaled (262) and stored (264) as a new leakage calibration signal if the variance is within acceptable limits (262). In a hybrid embodiment, the stored leakage signal (364) is converted to analog form (366), subtracted (301) from the analog down-converted radar signal (300), and scaled by a variable gain (303) before the complex I/Q components are sampled therefrom (302, 304). A leakage calibration process (350) is activated every Nth scan (316), wherein for each beam location, M chirp waveforms are averaged (352) and checked for variance (354). If the variance is within acceptable limits, the leakage signal is updated by a Kalman Filter (356), stored as the new leakage calibration signal (364), and the Kalman gain matrices are updated (358).

대표청구항 ▼

[ We claim:] [1.] A method of removing leakage in a continuous wave radar system, comprising:a. sampling the in-phase and quadrature-phase components of a down-converted radar return signal, each said component comprising an associated waveform comprising a repetitive sequence of frequencies;b. subt

[ We claim:] [1.] A method of removing leakage in a continuous wave radar system, comprising:a. sampling the in-phase and quadrature-phase components of a down-converted radar return signal, each said component comprising an associated waveform comprising a repetitive sequence of frequencies;b. subtracting the in-phase and quadrature-phase components of a stored leakage signal to form a resultant signal;c. comparing at least one first measure from said resultant signal with a corresponding at least one first threshold; andd. performing a leakage calibration if said at least one first measure exceeds said corresponding at least one threshold for m of N successive samples of said radar return signal, wherein said leakage calibration comprises:i). calculating a running average of successive said in-phase waveforms of said down-converted radar return signal by averaging respective elements of said repetitive sequence across successive repetitive sequences so as to generate associated averaged in-phase waveform;ii). calculating a running average of successive said quadrature-phase waveforms of said down-converted radar return signal by averaging respective elements of said repetitive sequence across successive repetitive sequences so as to generate associated averaged quadrature-phase waveform, said in-phase waveform and said quadrature-phase waveform constituting an averaged leakage signal;iii). calculating at least one variance waveform associated with said averaged leakage signal;iv). comparing at least one second measure of said at least one variance waveform with a corresponding at least one second threshold; andv). storing said averaged leakage signal as said stored leakage signal if said at least one second measure of said at least one variance waveform is less than said corresponding at least one second threshold.