A radar system injects a calibrated current at a signal generator during a reset portion and acquisition portion of each chirp period. The signal generator employs gear-switching to reduce PLL bandwidth during an acquisition phase and to increase the phase lock loop (PLL) bandwidth during a reset phase. By employing gear switching to change the bandwidth of the PLL circuit during the different portions of each chirp period, the length of the reset period is reduced, thus improving overall efficiency of the radar system while maintaining good performance.

Methods, systems, and devices for wireless communications are described. User equipment (UE), such as vehicles, may implement radar transmissions to detect and avoid potential collisions with a target such as other UE or pedestrians. A first UE may receive an indication of a location of a second UE and an indication of one or more parameters associated with radar transmission from the second UE. The first UE may also receive a radio frequency waveform that includes a first component associated with the radar transmissions from the second UE and a second component that is associated with reflected radar transmission from the first UE. The first UE may compensate for an interference from the first component based on the location of the second UE and the one or more parameters. The first UE may generate a radar image from the received radio frequency waveform based on compensating for the interference.

Examples disclosed herein relate to a radiating structure. The radiating structure has a transmission array structure having a plurality of transmission paths with each transmission path having a plurality of slots and a pair of adjacent transmission paths forming a superelement. Each superelement has a phase control module to control a phase of a transmission signal. The radiating structure also includes a radiating array structure having a plurality of radiating elements configured in a lattice, with each radiating element corresponding to at least one slot from the plurality of slots and the radiating array structure positioned proximate the transmission array structure. A feed coupling structure is coupled to the transmission array structure and adapted for propagation of a transmission signal to the transmission array structure. The transmission signal is radiated through at least one superelement and at least one of the plurality of radiating elements and has a phase controlled by the phase control module in the at least one superelement.

A radar system includes a transmitter including a power amplifier (PA) for amplifying a local oscillator (LO) signal, to generate an amplified signal. The radar system also includes a receiver including an IQ generator for generating an I signal based on the LO signal and for generating a Q signal based on the LO signal and a low noise amplifier (LNA) for amplifying a looped back signal, to generate a receiver signal. The receiver also includes a first mixer for mixing the receiver signal and the I signal, to generate a baseband I signal and a second mixer for mixing the receiver signal and the Q signal, to generate a baseband Q signal. Additionally, the radar system includes a waveguide loopback for guiding the amplified signal from the transmitter to the receiver as the looped back signal.

A communication unit (700) is described that includes a plurality of cascaded devices that comprise at least one master device (710) and at least one slave device (720, 723) configured in a master-slave arrangement. The at least one master device (710) and at least one slave device (720, 723) each comprise: an analog-to-digital converter, ADC, (741, 742) configured to use a same re-created system clock signal (788, 790) to align respective sampling instants between each ADC (741, 742). The at least one master device (710) comprises: a clock generation circuit comprising an internally-generated reference phase locked loop circuit (708), configured to output a system clock signal (782, 784); and a modulator circuit (762) coupled to the clock generation circuit and configured to receive and distribute the system clock signal (784). The at least one master device (710) and at least one slave device (720, 723) each comprise: a demodulator circuit (764, 765) configured to receive the distributed system clock signal (784) and re-create therefrom a synchronized system clock signal (788, 790) used by a respective ADC, (741, 742) of each of the the master device (710) and at least one slave device (720).

A method for the use in a radar system is described herein. In accordance with one embodiment, the method includes providing a local oscillator signal to an RF output channel of a radar system. The RF output channel is configured to generate, in an enabled state, an RF output signal based on the local oscillator signal. The method further includes determining a first measurement signal based on the local oscillator signal and a first representation of the RF output signal, while the RF output channel is disabled, and thus the first measurement signal represents crosstalk. Further, the method includes determining a second measurement signal based on the local oscillator signal and a second representation of the RF output signal while the RF output channel is enabled. A phase value associated with the RF output channel is determined based on the first measurement signal and the second measurement signal.

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.

A radar system is provided that includes transmission signal generation circuitry, a transmit channel coupled to the transmission generation circuitry to receive a continuous wave test signal, the transmit channel configurable to output a test signal based on the continuous wave signal in which a phase angle of the test signal is changed in discrete steps within a phase angle range, a receive channel coupled to the transmit channel via a feedback loop to receive the test signal, the receive channel including an in-phase (I) channel and a quadrature (Q) channel, a statistics collection module configured to collect energy measurements of the test signal output by the I channel and the test signal output by the Q channel at each phase angle, and a processor configured to estimate phase and gain imbalance of the I channel and the Q channel based on the collected energy measurements.

An object is to enable measurement of position and velocity of a measurement object.

A velocity measurement device includes a transmitting means, a receiving means, and a signal processing means. The transmitting means transmits a transmission signal by a transmitting antenna toward a measurement object. The receiving means receives a reflected wave from the measurement object with multiple receiving antennas and generates a reception signal for each of the receiving antennas. The signal processing means obtains a phase plane of the reflected wave with respect to an antenna plane of the multiple receiving antennas from a phase difference between the reception signals to specify an arrival direction of the reflected wave, obtains a distance to the measurement object from a propagation delay time of the reflected wave, and calculates a phase fluctuation of the reflected wave to calculate a velocity of the measurement object from the phase fluctuation.

Disclosed are various embodiments for improving the accuracy of a phase associated with the radar signal by identifying a spectral signature associated with a radio frequency (RF) impairment and performing digital predistortion to enhance the radar performance and to compensate for the impairment that causes offset or imbalance of the phase rotator output cause signal distortion or otherwise degrade of the phase of the signal. The self-calibrating mechanism of the present disclosure is configured to identify the impairments, determine a spectral signature associated with the impairment, and optimize the phase error through digital predistortion of the RF signal based at least in part on the spectral signature associated with the impairment.