An example apparatus includes a transducer to receive a reference signal and a reflected signal, the reflected signal being the reference signal after being reflected of a target; a filter to generate a band-pass reference signal and a band-pass reflected signal by filtering (A) reference signal samples associated with the reference signal and (B) reflected signal samples associated with the reflected signal; a correlator to generate a first correlation by correlating the reference signal samples with the reflected signal samples and a second correlation by correlating the band-pass reference signal with the band-pass reflected signal; and a delay estimator to determine a distance to the target based on the first correlation (coarse delay) and the second correlation (fine delay) and output a signal including the distance to the target.

A six-port self-injection-locked (SIL) radar includes an oscillation element, an antenna element, a six-port frequency demodulation element and a signal processing element. Because of a coupler and a phase shifter of the six-port frequency demodulation element, the signal processing element can extract vibration information of subject by using only two demodulated signals output from the six-port frequency demodulation element. As a result, the operation frequency of the six-port SIL radar is not limited by hardware architecture, and the hardware costs and the power consumption are also reduced.

A phased-array Doppler radar includes a two-way splitter, a transmit antenna, a receive antenna array, an ILO, a demodulation unit and a digital signal processing unit. A reference signal is split by the two-way splitter to the transmit antenna for transmission to targets and the ILO for injection locking. Signals reflected by the targets are received by the receive antenna array as received signals. An injection-locked signal generated by the ILO and the received signals received by the receive antenna array are delivered to the demodulation unit. The received signals are demodulated into baseband I/Q signals by the demodulation unit that uses the injection-locked signal as a local oscillator signal. The baseband I/Q signals are processed by the digital signal processing unit to obtain a digital beamforming pattern.

A device may include a test signal generator and a receive antenna input. The device may include a switchable impedance matching circuit, coupled to the test signal generator and to a receive chain, to cause an impedance matching between the test signal generator and a component of the receive chain to be increased during a monitoring phase. The impedance matching during the monitoring phase enables one or more measurements based on a test signal generated by the test signal generator. The switchable impedance matching circuit may cause a partial impedance mismatching between the test signal generator and the component of the receive chain during a verification phase associated with verifying a return of the switchable impedance matching circuit to an impedance matching caused during the operational phase. The device may include a control circuit to verify operation of the returning of the switchable impedance matching circuit in the verification phase.

A radio-frequency receiver includes built-in-self-test (BIST) circuitry which generates a self-test signal. A local oscillator signal is divided. A self-test oscillation signal is generated, based, at least in part, on the frequency-divided local oscillation signal. The self-test signal is generated based on the self-test oscillation signal. The BIST circuitry includes a divider, which divides the self-test oscillation signal. The frequency-divided local oscillation signal and the divided self-test oscillation signal are used to perform one or more of generating the self-test oscillation signal and controlling the generation of the self-test oscillation signal. The radio-frequency receiver may be an automotive radar receiver.

This description relates to a method for suppressing intermodulation distortion in a digital output signal of a radar device. In one implementation, the method includes—in a first mode—feeding a test signal into a receiving channel, the test signal is fed to a mixer contained in the receiving channel and is downconverted to a baseband, a baseband signal that includes intermodulation products on account of a nonlinearity of the transfer characteristic of the receiving channel being provided at the mixer output. The digital output signal is generated based on the baseband signal. The method further includes—in the first mode—determining an intermodulation product and, on the basis thereof, ascertaining a parameter of a model characterizing the nonlinearity. In a second mode, in which an antenna signal is fed to the mixer—suppressing the intermodulation product in the digital output signal based on the parameter and the baseband signal.

A test system for testing a radar sensor comprising a test chamber for encompassing a radar sensor to be tested. A test location is provided within the test chamber on which the radar sensor to be tested is placed for testing. Further, the test system comprises at least one antenna unit and at least one first radar target simulator connected to the antenna unit. The test system also comprises at least one antenna array different to the antenna unit and at least one second radar target simulator connected to the antenna array.

A device may include a test signal generator and a receive antenna input. The device may include a switchable impedance matching circuit, coupled to the test signal generator and to a receive chain, to cause an impedance matching between the test signal generator and a component of the receive chain to be increased during a monitoring phase. The impedance matching during the monitoring phase enables one or more measurements based on a test signal generated by the test signal generator. The switchable impedance matching circuit may cause a partial impedance mismatching between the test signal generator and the component of the receive chain during a verification phase associated with verifying a return of the switchable impedance matching circuit to an impedance matching caused during the operational phase. The device may include a control circuit to verify operation of the returning of the switchable impedance matching circuit in the verification phase.

A phased-array Doppler radar includes a two-way splitter, a transmit antenna, a receive antenna array, an ILO, a demodulation unit and a digital signal processing unit. A reference signal is split by the two-way splitter to the transmit antenna for transmission to targets and the ILO for injection locking. Signals reflected by the targets are received by the receive antenna array as received signals. An injection-locked signal generated by the ILO and the received signals received by the receive antenna array are delivered to the demodulation unit. The received signals are demodulated into baseband I/Q signals by the demodulation unit that uses the injection-locked signal as a local oscillator signal. The baseband I/Q signals are processed by the digital signal processing unit to obtain a digital beamforming pattern.

A method includes receiving, at a radar timing card, radar timing information and a synchronous clock signal. The method also includes generating, using the radar timing card, a timing trigger to indicate a time of transmission for radar return information. The method further includes receiving, at each of multiple digital-to-analog converter (DAC) channels of one or more DAC cards, the synchronous clock signal and the timing trigger. In addition, the method includes simultaneously transmitting, from each of the DAC channels, a dedicated portion of the radar return information based on the time of transmission indicated by the timing trigger. The synchronous clock signal is used to align the simultaneous transmissions of the DAC channels on the one or more DAC cards.