Patent ID: 11947034
Assignee: INFINEON TECHNOLOGIES AG
Field: Measurement (Instruments)
Classification: CPC G | IPC G

Claim 9:
10. A method of operating a frequency-modulated continuous-wave (FMCW) radar system having multiple receiving (Rx) channels, the method comprising:
calibrating the FMCW radar system, comprising:
setting the Rx channels in a calibration mode, wherein each of the Rx channels includes a mixer, a programmable phase shifter coupled to a first input terminal of the mixer, a filter coupled to an output terminal of the mixer, and an analog-to-digital converter (ADC) coupled to an output terminal of the filter;
sweeping a value of a phase shifter control word of the programmable phase shifter in each of the Rx channels across a range of values, wherein the value of the phase shifter control word sets a phase shift in the programmable phase shifter, wherein the sweeping comprises, for each of the Rx channels:
setting a value for the phase shifter control word of the programmable phase shifter;
sending a chirp signal to the programmable phase shifter;
sending a modulated chirp signal to a second input terminal of the mixer, wherein an output signal at the output terminal of the mixer comprises a beat signal; and
for each of the range of values of the phase shifter control word, forming an amplitude curve based on data samples from the ADC in the Rx channel, wherein the amplitude curve illustrates amplitudes of the beat signal at a plurality of frequencies within an operating frequency band of the FMCW radar system; and

after forming the amplitude curve, for each of the Rx channels and for each frequency of the plurality of frequencies, performing a curve fitting to generate a phase response curve using the amplitudes of the beat signal at the range of values of the phase shifter control word, wherein the phase response curve illustrates phases of the Rx channel for the range of values of the phase shifter control word.