A radar system includes a radar transceiver device, which includes a transmitter front end circuit for transmitting a chirp signal towards an object. The radar transceiver device includes a receiver front end circuit for receiving the reflected chirp signal from the object. The radar transceiver device includes a voltage controlled oscillator (VCO) to generate a transmitted chirp signal. The radar transceiver device includes a mixer configured to generate four intermediate frequency output signals having different phases. The radar system includes a controller device, which includes a processor, and a memory for storing the intermediate frequency output signals and instructions for executing in the processor. The instructions cause the processor to generate a complex Fast Fourier Transform (FFT) result by performing a FFT of the intermediate frequency output signals while using zero-padding. The instructions cause the processor to determine, using interpolation, a maximum amplitude in the FFT result and identifying the frequency corresponding to the maximum amplitude. The instructions cause the processor to calculate a distance to the object using the determined frequency.

A radar ranging method includes: obtaining a first signal, where the first signal is a frequency domain signal obtained after low frequency suppression is performed in a beat frequency signal, and the beat frequency signal is a signal obtained by mixing a transmitted signal transmitted by a frequency modulated continuous wave FMCW radar and a received echo signal; performing mean gradient calculation on the first signal in frequency domain to obtain a second signal; and calculating at least one of a speed or a distance of a target object based on a peak signal in the second signal.

A system identifies and localizes an object. The system contains a bistatic FMCW radar sensor system having two FMCW radar sensors and is configured to operate coherently or quasi-coherently and to emit a series of repeating ramp signals. An active RFID transponder is disposed on an object to be identified and to be localized and is configured to produce a modulated bistatic backscatter signal. A ramp signal sent out by the radar sensors at a ramp repetition frequency is modulated with an amplitude modulation signal, the modulation frequency is less than half the ramp repetition frequency. An evaluation unit establishes an association between a beat frequency and the modulation frequency of the active RFID transponder, which modulation frequency is already known, on the basis of the modulated bistatic backscatter signal by two Fourier transforms of the modulated backscatter signal according to the frequency and to the amplitude.

An example radar device includes an antenna system, a transmitter having an input, and an output coupled to an input of the antenna system, the transmitter having modulation circuitry to provide frequency modulated continuous wave (FMCW) signals for transmission by the antenna system; a receive signal processing chain; and a digital front-end. The receive signal processing chain includes an input coupled to an output of the antenna system, and is configured to receive radar reflection signals, process the radar reflected signals to generate an intermediate frequency (IF) baseband signal, and digitize the IF baseband signal to generate digital samples of the IF baseband signal. The digital front-end has an input to receive the digital samples of the IF baseband signal and to phase-shift the digital samples in response to a calibration signal.

A method for calibrating a receiving (Rx) channel of a frequency-modulated continuous-wave (FMCW) radar system includes: setting the Rx channel in calibration mode, where the Rx channel includes a mixer, a phase shifter coupled to a first input of the mixer, a filter coupled to an output of the mixer, and an analog-to-digital converter (ADC) coupled to an output of the filter; setting a value for a phase shifter control word of the phase shifter; sending a chirp signal to the phase shifter; sending a modulated chirp signal to a second input of the mixer, where an output signal at the output of the mixer includes a beat signal; and forming an amplitude curve based on data samples from the ADC, where the amplitude curve illustrates amplitudes of the beat signal at a plurality of frequencies within an operating frequency band of the FMCW radar system.

Various embodiments include methods and systems having detection apparatus operable to cancel or reduce leakage signal originating from a source signal being generated and transmitted from a transmitter. A leakage cancellation signal can be generated digitally, converted to an analog signal, and then subtracted in the analog domain from a received signal to provide a leakage-reduced signal for use in detection and analysis of objects. A digital cancellation signal may be generated by generating a cancellation signal in the frequency domain and converting it to the time domain. Optionally, an estimate of a residual leakage signal can be generated and applied to reduce residual leakage remaining in the leakage-reduced signal. Additional apparatus, systems, and methods can be implemented in a variety of applications.

A method for calibrating a cascaded radar system includes transmitting first radar transmission signal from a radar device. First radar reflection signals corresponding to the respective first radar transmission signal reflected from calibration target are received at each of the radar devices. The first radar reflection signals are demodulated to generate first baseband signals at each of the radar devices. A second radar transmission signal is modulated with respect to the first radar transmission signal at the respective one of the radar devices. The second radar transmission signal is transmitted from the respective one of the radar devices and are received as second radar reflection signals at each of the radar devices. The second radar reflection signals are demodulated to generate second baseband signals at each of the radar devices, and each of the radar devices are calibrated based on the first and second baseband signals.

Aspects of the present disclosure are directed to radar apparatuses and related methods. As may be implemented in connection with one or more embodiments, frequency-based representations of reflected radar signals received by different radar receivers are processed utilizing superposition of and combining of respective ones of the frequency-based representations. In response to said processing, phase noise in the frequency-based representations of reflected radar signals is corrected.

There is provided a radar device. An extracting unit extracts history peak signals according to estimated peak signals, from a difference frequency between a transmission signal and a reception signal obtained by receiving a reflected wave of a transmission wave based on the transmission signal from a target, in a first period and a second period. An estimating unit estimates current peak signals as the estimated peak signals based on extracted previous peak signals. A pairing unit pairs the history peak signal of the first period and the history peak signal of the second period. A re-pairing unit re-pairs the paired history peak signals, based on peak signals existing in a predetermined range including the paired history peak signals. An information generating unit generates information on the target based on a result of the pairing and a result of the re-pairing.

There is provided a radar device. An estimating unit estimates peak signals corresponding to a target in the latest periods of each of UP and DOWN beat sections of a beat signal on the basis of histories of peak signals corresponding to the target in past periods of the UP and DOWN beat sections. A pairing unit extracts peak signals within predetermined ranges defined with reference to the estimate peak signals on the basis of the histories, and pairs the extracted peak signals. In a case where a distance to the target is equal to or shorter than a predetermined value, the pairing unit extracts peak signals corresponding to the target, from a first range which is a predetermined angular range defined with reference to the estimate peak signals, or a second range which is a predetermined transverse position range defined with reference to the estimate peak signals.