Frequency and time offset modulation (FANTOM) chirp MIMO automotive radar with N-path notch filter

A radar system, comprising:

• a reference signal generator configured to produce a reference signal comprising a sequence of waveforms;
• a transmit module configured to produce a plurality of frequency and time offset modulation (FanTOM) signals from the reference signal and to transmit the plurality of FanTOM signals as N radio-frequency encoded transmit signals over a corresponding plurality of N transmitters, wherein each transmitter is configured to transmit an associated FanTOM signal at a distinct time;
• at least a first receiver module, comprising:
• a first receive antenna configured to receive a target return signal reflected from the N radio-frequency encoded transmit signals by at least one target,
• a mixer circuit configured to mix the target return signal with the reference signal to produce an intermediate frequency signal,
• a bank of one or more notch filters configured to produce a filtered intermediate frequency signal from the intermediate frequency signal, where the bank of one or more notch filters is clocked with a sampling clock frequency FCLOCK to control harmonic notch frequencies of the bank of one or more notch filters, and
• an analog-to-digital converter configured to convert the filtered intermediate frequency to a digital signal, where the analog-to-digital converter is clocked with a sampling clock frequency of at least FCLOCK;
• and
• a radar control processing unit configured to process the digital signal to generate a range spectrum comprising N segments that correspond, respectively, to the N radio frequency encoded transmit signals transmitted over the N transmitters.

A radar system comprising:

• a plurality of transmitters, wherein each transmitter is configured to:
• receive a linear frequency modulation (LFM) reference chirp signal,
• generate a frequency offset signal from the reference signal, wherein each transmitter of the plurality of transmitters is associated with a distinct frequency offset from the LFM reference chirp signal, and
• transmit the frequency offset signal as a RF encoded transmit signal at a distinct time for that transmitter, wherein the difference in the starting time of the transmission for each transmitter is at least equivalent to a round trip delay associated with a predetermined maximum range of the radar system;
• a plurality of receivers, wherein each receiver is configured to:
• receive, at an antenna, a target return signal reflected from the RF encoded transmit signals associated with the plurality of transmitters,
• mix the target return signal with the LFM reference chirp signal to produce an intermediate frequency signal,
• filter the intermediate frequency signal with at least a bank of one or more multi-path notch filters configured to produce a filtered intermediate frequency signal from the intermediate frequency signal, where the bank of one or more multi-path notch filters is clocked with a sampling clock frequency FCLOCK to control harmonic notch frequencies which suppress transmitter spill-over and close-in self-clutter interference, and
• convert the filtered intermediate frequency signal to a digital signal with an analog-to-digital converter clocked with a sampling clock frequency of at least FCLOCK;
• and
• a radar control processing unit configured to process the digital signal to generate a range spectrum comprising a first plurality of segments that correspond, respectively, to the RF encoded transmit signals by the plurality of transmitters.