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

Claim 0:
1. A method of calibrating a receiving (Rx) channel of a frequency-modulated continuous-wave (FMCW) radar system, the method comprising:
performing a first measurement of the Rx channel by:
sending a chirp signal through a first signal path to a first input terminal of a mixer of the Rx channel, wherein the first signal path comprises a modulation circuit that modulates the chirp signal with a modulating signal to generate a modulated chirp signal;
sending the chirp signal through a second signal path to a second input terminal of the mixer, wherein the second signal path comprises a phase shifter that introduces a phase shift to the chirp signal in accordance with a phase shifter control word of the phase shifter, wherein the phase shifter control word has a first value for the first measurement;
filtering an output signal of the mixer using a filter;
sampling an output signal of the filter to generate digital samples using an analog-to-digital converter (ADC), wherein the output signal of the filter comprises a modulated beat signal that is a beat signal modulated by the modulating signal; and
determining a first curve using the digital samples, wherein the first curve illustrates amplitudes of the modulated beat signal at a plurality of frequencies within a frequency band of the chirp signal when the phase shifter control word has the first value;

performing a second measurement of the Rx channel and determining a second curve that illustrates the amplitudes of the modulated beat signal at the plurality of frequencies when the phase shifter control word has a second value, wherein the second measurement is performed using a same method as the first measurement but with the phase shifter control word having the second value; and
for each frequency of the plurality of frequencies, generating a phase response curve using at least the amplitudes of the modulated beat signal in the first curve and the second curve that correspond to the each frequency, wherein the phase response curve illustrates phases of the Rx channel for different values of the phase shifter control word.