A radio frequency (RF) circuit includes a signal path coupled between two RF inputs and at least one baseband output terminal. The signal path includes a 90° hybrid coupler including a first port that receives a first RF signal and a second port that receives a second RF signal. The 90° hybrid coupler generates a first coupler output signal based on the first RF signal and the second RF signal and generates a second coupler output signal based on the first RF signal and the second RF signal. The signal path includes a quadrature down-converter configured to down-convert the first coupler output signal into a first baseband signal and down-convert the second coupler output signal into a second baseband signal. The RF circuit includes a baseband combiner circuit configured to combine the first baseband signal and the second baseband signal to generate at least one of output signal.

A device may include a receive antenna input to couple a receive chain of the device to a receive antenna. The device may include a test signal generator. The device may include a switchable impedance matching circuit coupled to the test signal generator and to the receive chain to cause an impedance matching between the test signal generator and at least one component of the receive chain to depend on an impedance of the receive antenna in an antenna monitoring phase. The antenna monitoring phase may be associated with determining an impedance mismatching of the receive antenna. The device may include a control circuit to determine the impedance mismatching of the receive antenna in the antenna monitoring phase.

A radar system is provided that includes a first radar transceiver integrated circuit (IC) including transmission signal generation circuitry operable to generate a continuous wave signal and a first transmit channel coupled to the transmission generation circuitry to receive the continuous wave signal and transmit a test signal based on the continuous wave signal, and a second radar transceiver IC including a first receive channel coupled to an output of the first transmit channel of the first radar transceiver IC via a loopback path to receive the test signal from first the transmit channel, the second radar transceiver IC operable to measure phase response in the test signal.

Disclosed is an ultra-wideband integrated circuit having a transmitter, a receiver, and a non-volatile memory configured to store a time-of-flight between the transmitter and receiver. Also included is an interface configured to communicate with a processor configured to calculate the time-of-flight. Further included is a digital transceiver configured, in response to a loopback mode, to cause the transmitter to transmit a plurality of ultra-wideband frames directly to the receiver, measure a time-of-flight for each of the plurality of ultra-wideband frames received by the receiver and generate a data set for calculating the time-of-flight associated with each measured time-of-flight, send the data set to the processor, receive from the processor the time-of-flight calculated from the data set, and store the time-of-flight in the non-volatile memory.

An electronic device may include radar circuitry. Control circuitry may calibrate the radar circuitry using a multi-tone calibration signal. A first mixer may upconvert the calibration signal for transmission by a transmit antenna. A de-chirp mixer may mix the calibration signal output by the first mixer with the calibration signal as received by a receive antenna or loopback path to produce a baseband multi-tone calibration signal. The baseband signal will be offset from DC by the frequency gap. This may prevent DC noise or other system effects from interfering with the calibration signal. The control circuitry may sweep the first mixer over the radio frequencies of operation of the radar circuitry to estimate the power droop and phase shift of the radar circuitry based on baseband calibration signal. Distortion circuitry may distort transmit signals used in spatial ranging operations to invert the estimated power droop and phase shift.

A circuit includes a radio frequency (RF) channel including an input node and an output node and being configured to receive an RF oscillator signal at the input node and to provide an RF output signal at the output node; a mixer configured to mix an RF reference signal and an RF test signal representative of the RF output signal to generate a mixer output signal; an analog-to-digital converter configured to sample the mixer output signal in order to provide a sequence of sampled values; and a control circuit configured to provide a sequence of phase offsets by phase-shifting at least one of the RF test signal and the RF reference signal using one or more phase shifters, calculate a spectral value from the sequence of sampled values; and calculate estimated phase information indicating a phase of the RF output signal based on the spectral value.

A radio frequency (RF) system includes a radar monolithic microwave integrated circuit (MIMIC), which includes: a phase detector including a test input port, and a monitoring input port, wherein the phase detector is configured to generate an output signal that represents a phase difference between a test signal received at the test input port and a monitoring signal received at the monitoring input port; a test signal path including at least one active component, the test signal path configured to receive a local oscillator signal and provide the local oscillator signal as the test signal to the test input port during a first measurement interval; and a passive signal path configured to receive the local oscillator signal and provide the local oscillator signal to the monitoring input port as the monitoring signal during the first measurement interval.

An apparatus is for generating an emulated radar reflection signal of a target moving at a relative velocity. The apparatus includes a radar detector, an emulation transmitter, and a processor. The radar detector is configured to detect radar chirps emitted by a device under test (DUT), where the chirps are emitted at random time intervals. The emulation transmitter is configured to generate emulated radar reflection signals of the target being emulated. The processor is configured to generate control signals at intervals corresponding to the random time intervals at which the radar chirps are emitted by the DUT, where each control signal controls the emulation transmitter to generate a radar reflection signal. A relative phase of the control signals is adjusted according to a duration of each of the random time intervals between successive chirps and a magnitude and sign of the relative velocity of the target.

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.

Methods for monitoring of performance parameters of one or more receive channels and/or one or more transmit channels of a radar system-on-a-chip (SOC) are provided. The radar SOC may include a loopback path coupling at least one transmit channel to at least one receive channel to provide a test signal from the at least one transmit channel to the at least one receive channel when the radar SOC is operated in test mode. In some embodiments, the loopback path includes a combiner coupled to each of one or more transmit channels, a splitter coupled to each of one or more receive channels, and a single wire coupling an output of the combiner to an input of the splitter.