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.

Methods and apparatus for generating a target signal with desired phase shift information. In embodiments, a system receives an input target signal having a first frequency and combines the input target signal with an oscillator signal to generate a first output signal having a second frequency. The oscillator signal is generated using a digital component that imparts phase-shift information into the oscillator signal. The first output signal is combined with a fixed frequency oscillator signal to generate a second output signal corresponding to a signal reflected from a target.

In an embodiment, a method for testing a millimeter-wave radar module includes: providing power to the millimeter-wave radar module; performing a plurality of tests indicative of a performance level of the millimeter-wave radar module; comparing respective results from the plurality of tests with corresponding test limits; and generating a flag when a result from a test of the plurality of test is outside the corresponding test limits, where performing the plurality of tests includes: transmitting a signal with a transmitting antenna coupled to a millimeter-wave radar sensor, modulating the transmitted signal with a test signal, and capturing first data from a first receiving antenna using an analog-to-digital converter of the millimeter-wave radar sensor, where generating the flag includes generating the flag based on the captured first data.

A self-testing measuring system includes at least three modes: an operating mode and at least two test modes. In a third test mode, a digital signal generating unit stimulates the digital input circuit directly by means of test signals. In a second test mode, the digital signal generating unit stimulates the analogue signal string and the digital input circuit by means of test signals. In a first test mode, the digital signal generating unit stimulates the analogue signal string, the measuring unit (typically an ultrasound transducer) and the digital input circuit by means of test signals, thereby allowing this signal string to be tested. In the operating mode, the digital signal generating unit stimulates the analogue signal string, the measuring unit (typically an ultrasound transducer) and the digital input circuit by means of output signals, thereby allowing the signal string to be monitored for parameter compliance.

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.

In an embodiment, a method for testing a millimeter-wave radar module includes: providing power to the millimeter-wave radar module; performing a plurality of tests indicative of a performance level of the millimeter-wave radar module; comparing respective results from the plurality of tests with corresponding test limits; and generating a flag when a result from a test of the plurality of test is outside the corresponding test limits, where performing the plurality of tests includes: transmitting a signal with a transmitting antenna coupled to a millimeter-wave radar sensor, modulating the transmitted signal with a test signal, and capturing first data from a first receiving antenna using an analog-to-digital converter of the millimeter-wave radar sensor, where generating the flag includes generating the flag based on the captured first data.

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.

An object sensor test system includes a sensor and a test bench. The sensor includes a receiver configured to receive a simulated optical signal and a processing chain that includes a plurality of processing components configured to process at least one measurement signal generated in response to the simulated optical signal to generate processed test data. The sensor also includes a test interface configured to receive a control signal, and selectively extract processed test data at a selected output of the processing chain based on the control signal. The test bench is configured to transmit the control signal to the test interface, receive the processed test data from the sensor, compare the received processed test data with expected data to generate a comparison result, and determine that a segment of the processing chain is operating normally or abnormally based on the comparison result.

A circuit is described herein. In accordance with one embodiment the circuit includes two or more RF channels, wherein each channel includes an input node, a phase shifter and an output node. Each channel is configured to receive an RF oscillator signal at the input node and to provide an RF output signal at the output node. The circuit further includes an RF combiner circuit that is coupled with the outputs of the RF channels and configured to generate a combined signal representing a combination of the RF output signals, and a monitor circuit that includes a mixer and is configured to receive and down-convert the combined signal using an RF reference signal. Thus a mixer output signal is generated that depends on the phases of the RF output signals.

An object sensor test system includes a sensor and a test bench. The sensor includes a test interface configured to receive test data and at least one control signal, selectively inject the test data into a selected input of a processing chain based on the at least one control signal, and selectively extract processed test data at a selected output of the processing chain based on the at least one control signal. The test bench is configured to transmit the test data and the at least one control signal to the test interface, receive the processed test data from the sensor, compare the received processed test data with expected data to generate a comparison result, and determine that a segment of the processing chain is operating normally or abnormally based on the comparison result.