Patent ID: 11936418
Assignee: KAIKUTEK INC.
Field: Measurement (Instruments)
Classification: CPC H  G | IPC G  H

Claim 1:
2. A radar signal processing system with a self-interference cancelling function, receiving an original input signal through a receiver antenna, and comprising:
a control input end, receiving a control signal;
a signal input end, electrically connected to the receiver antenna and receiving the original input signal;
an analog front end (AFE) processor, electrically connected to the signal input end, and performing a front end process according to the original input signal and generating an analog input signal;
an analog to digital converter (ADC), electrically connected to the AFE processor, and converting the analog input signal to a digital input signal;
an adaptive interference canceller (AIC), electrically connected to the ADC, performing an adaptive interference cancellation process to the digital input signal, and generating a digital interference signal;
a digital to analog converter (DAC), electrically connected to the AIC, converting the digital interference signal to an analog interference signal, and outputting the analog interference signal to the AFE processor; and
a first switching module, connected to the DAC and the control input end, having a first output end and a second output end; wherein
the AFE processor cancels the analog interference signal from the original input signal while performing the front end process, and comprises:
a trans-impedance amplifier (TIA);
a first feedback unit, wherein the TIA is electrically connected to the signal input end through the first feedback unit, and the first feedback unit is also connected to the first output end of the first switching module;
a high-pass filter (HPF), electrically connected to the TIA and filtering the original input signal;
a second feedback unit, electrically connected to the second output end of the first switching module;
a second switching module, electrically connected to the control input end, and having a first input end, a second input end, and an output end; wherein the first input end is connected to the TIA, the second input end is connected to the HPF, and the output end is connected to the second feedback unit;
a programmable gain amplifier (PGA), electrically connected between the second feedback unit and the ADC;

when the control signal is a first value, the first switching module outputs the analog interference signal to the first feedback unit, and the first feedback unit cancels the analog interference signal from the original input signal, and outputs the original input signal after the cancellation to the TIA; the second switching module outputs the original input signal after the cancellation from the TIA to the second feedback unit, and the second feedback unit passes the original input signal after the cancellation to the PGA; and
when the control signal is a second value, the second switching module outputs the analog interference signal to the second feedback unit; wherein the TIA receives the original input signal through the first feedback unit, the HPF filters the original input signal, the second switching unit outputs the original input signal after filtering to the second feedback unit, and the second feedback unit cancels the analog interference signal from the original input signal after filtering, and outputs the original input signal after cancellation to the PGA.