Frequency-Modulated-Continuous-Wave (FMCW) radar with timing synchronization

A Frequency-Modulated-Continuous-Wave (FMCW) radar device, the device comprising:

• a clock to drive an oscillator, wherein the oscillator is configured to transmit a first signal from an RF antenna, and wherein a frequency of the first signal varies over a first frequency range around a first baseband frequency;
• a mixer configured to receive a second signal from the RF antenna and generate a difference signal based on the first signal and the second signal, wherein a frequency of the second signal varies over a second frequency range around a second baseband frequency;
• an analog-to-digital converter configured to generate a digital difference signal based on the difference signal generated by the mixer;
• and
• a signal processing unit, wherein the signal processing unit is configured to:
• determine values of a plurality of parameters including a first timing offset based on the digital difference signal, wherein the first timing offset comprises a first time-of-flight delay and a first clock offset of the first FMCW radar unit at a first time;
• receive a second timing offset of a second FMCW radar unit, wherein the second timing offset of the second FMCW radar unit comprises a second time-of-flight delay and a second clock offset at a second time;
• determine a third clock offset based on a difference between the first timing offset and the second timing offset;
• and
• synchronize the clock with a clock of the second FMCW radar unit based on the third clock offset.

A Frequency-Modulated-Continuous-Wave (FMCW) radar system, the system comprising:

• a plurality of FMCW radar units, wherein each FMCW radar unit of the plurality of FMCW radar units comprise:
• a clock configured to drive an oscillator, wherein the oscillator is configured to transmit a first signal from an RF antenna, and wherein a frequency of the first signal varies over a first frequency range around a first baseband frequency;
• a mixer configured to receive a second signal from the RF antenna and generate a difference signal based on the first signal and the second signal, wherein a frequency of the second signal varies over a second frequency range around a second baseband frequency;
• an analog-to-digital converter (ADC) configured to generate a digital difference signal based on the difference signal generated by the mixer;
• and
• a signal processing unit, wherein the signal processing unit is configured to:
• determine values of a plurality of parameters including a first timing offset based on the digital difference signal, wherein the first timing offset comprises a first time-of-flight delay and a first clock offset at a first time;
• receive a second timing offset, wherein the second timing offset comprises a second time-of-flight delay and a second clock offset at a second time;
• determine a third clock offset based on a difference between the first timing offset and the second timing offset;
• and synchronize the clock with the third clock offset.