Switchable FMCW/PMCW radar transceiver
Automotive radar methods and systems for enhancing resistance to interference using a built-in self-test (BIST) module. In one illustrative embodiment, an automotive radar transceiver includes: a signal generator that generates a transmit signal; a modulator that derives a modulated signal from the transmit signal using at least one of phase and amplitude modulation; at least one receiver that mixes the transmit signal with a receive signal to produce a down-converted signal, the receive signal including the modulated signal during a built-in self-test (BIST) mode of operation; and at least one transmitter that drives a radar antenna with a selectable one of the transmit signal and the modulated signal.
1. A method of operating a radar transceiver, the method comprising:
generating a transmit signal, the transmit signal being coupled to a mixer in a receiver to down-convert a receive signal;
modulating the transmit signal using phase modulation to produce a modulated signal;
injecting the modulated signal into the receive signal during a built-in self-test (BIST);
verifying operation of the receiver during the built-in self-test; and
selecting a frequency modulation or phase modulation transmission mode, wherein said selecting includes:
transmitting the transmit signal, the transmit signal including a chirp waveform;
processing the down-converted receive signal to determine a distance to a reflector;
if the down-converted receive signal is indicative of interference, selecting the phase modulation transmission mode; and
if the down-converted receive signal is not indicative of interference, selecting the frequency modulation transmission mode.
2. The method of claim 1 , further comprising: transmitting the transmit signal in the frequency modulation transmission mode, the transmit signal including a chirp waveform.
3. The method of claim 1 , further comprising: transmitting the modulated signal in the phase modulation transmission mode.