Abstract: Example radar apparatuses including a phase lock loop circuit used for processing both transmission signals and reflection signals are provided herein. An example apparatus includes a transmit signal generator electrically connected to an antenna and configured to generate a transmission signal at a transmit frequency, a receiver circuit electrically connected to the antenna and configured to receive a radar return signal and downconvert the radar return signal at a downconvert frequency for signal processing, and a phase lock loop circuit configured to be tuned to output both at the transmit frequency for transmission of the transmission signal by the antenna and the downconvert frequency for downconverting a frequency of the radar return signal for further signal processing. The transmit frequency is different from the downconvert frequency.

Abstract: Example radar apparatuses including a phase lock loop circuit used for processing both transmission signals and reflection signals are provided herein. An example apparatus includes a transmit signal generator electrically connected to an antenna and configured to generate a transmission signal at a transmit frequency, a receiver circuit electrically connected to the antenna and configured to receive a radar return signal and downconvert the radar return signal at a downconvert frequency for signal processing, and a phase lock loop circuit configured to be tuned to output both at the transmit frequency for transmission of the transmission signal by the antenna and the downconvert frequency for downconverting a frequency of the radar return signal for further signal processing. The transmit frequency is different from the downconvert frequency.

Abstract: Various implementations described herein are directed to frequency correction for pulse compression radar. In one implementation, a method may include generating a first transmission signal using a pulse compression radar system based on an ideal waveform signal. The method may also include measuring a frequency of the first transmission signal at an output of a transmitter module. The method may further include comparing the measured frequency of the first transmission signal and a frequency of the ideal waveform signal. The method may additionally include generating pre-distortion coefficients based on the comparison, where the pre-distortion coefficients are configured to compensate for a difference between the measured frequency of the first transmission signal and the frequency of the ideal waveform signal. In addition, the method may include generating a compensated transmission signal using the pulse compression radar system based on the pre-distortion coefficients and the ideal waveform signal.

Abstract: Various implementations described herein are directed to adaptive frequency correction for pulse compression radar. In one implementation, a method may include generating a first transmission signal using a first direct digital synthesizer of a pulse compression radar system based on frequency sweep coefficients. The method may also include comparing a frequency of the first transmission signal at a feedback loop of a phase locked loop circuit and a frequency of an ideal waveform signal. The method may further include generating adaptive frequency coefficients based on the comparison, where the adaptive frequency coefficients are configured to compensate for a difference between the frequency of the first transmission signal at the feedback loop and the frequency of the ideal waveform signal. The method may additionally include generating a compensated transmission signal using the pulse compression radar system based on the adaptive frequency coefficients and the frequency sweep coefficients.

Abstract: A system that has a chirp generator for emitting signals and an amplitude modulator for shaping the signals emitted by the chirp generator. The signals are shaped using a calibration ramp. The system further includes a Radio Frequency (RF) power amplifier for amplifying the signals shaped by the amplitude modulator, an RF power detector for measuring power levels of the signals amplified by the RF power amplifier, and a pre-distortion coefficient generator for adjusting the measured power levels using power detector calibration coefficients that correspond to the RF power detector.

Abstract: Various implementations described herein are directed to an apparatus having a transmit signal generator for a pulse compression radar. The transmit signal generator may include a frequency modulation stage with phase-lock-loop (PLL) circuitry configured to generate a transmit signal at antenna frequency. The transmit signal generator may include an amplitude modulation stage configured to shape an amplitude of the generated transmit signal.

Abstract: An FMCW radar system includes received signal processing arranged to apply multiple window functions in parallel to a received beat signal including at least one window function having a narrower main-lobe in its frequency response than at least one other window function and said at least one other window function having relatively higher side-lobe attenuation in its frequency response, transform the output of the multiple window functions from the time domain to the frequency domain, and combine the outputs of the transforms for further processing. Both narrow frequency resolution and thus good range discrimination, and also good side-lobe attenuation to avoid close interference are achieved.

Abstract: Various implementations described herein are directed to an apparatus having a transmit signal generator for a pulse compression radar. The transmit signal generator may include a frequency modulation stage with phase-lock-loop (PLL) circuitry configured to generate a transmit signal at antenna frequency. The transmit signal generator may include an amplitude modulation stage configured to shape an amplitude of the generated transmit signal.

Abstract: Various implementations described herein are directed to frequency correction for pulse compression radar. In one implementation, a method may include generating a first transmission signal using a pulse compression radar system based on an ideal waveform signal. The method may also include measuring a frequency of the first transmission signal at an output of a transmitter module. The method may further include comparing the measured frequency of the first transmission signal and a frequency of the ideal waveform signal. The method may additionally include generating pre-distortion coefficients based on the comparison, where the pre-distortion coefficients are configured to compensate for a difference between the measured frequency of the first transmission signal and the frequency of the ideal waveform signal. In addition, the method may include generating a compensated transmission signal using the pulse compression radar system based on the pre-distortion coefficients and the ideal waveform signal.

Abstract: A system that has a chirp generator for emitting signals and an amplitude modulator for shaping the signals emitted by the chirp generator. The signals are shaped using a calibration ramp. The system further includes a Radio Frequency (RF) power amplifier for amplifying the signals shaped by the amplitude modulator, an RF power detector for measuring power levels of the signals amplified by the RF power amplifier, and a pre-distortion coefficient generator for adjusting the measured power levels using power detector calibration coefficients that correspond to the RF power detector.

Abstract: Various implementations described herein are directed to adaptive frequency correction for pulse compression radar. In one implementation, a method may include generating a first transmission signal using a first direct digital synthesizer of a pulse compression radar system based on frequency sweep coefficients. The method may also include comparing a frequency of the first transmission signal at a feedback loop of a phase locked loop circuit and a frequency of an ideal waveform signal. The method may further include generating adaptive frequency coefficients based on the comparison, where the adaptive frequency coefficients are configured to compensate for a difference between the frequency of the first transmission signal at the feedback loop and the frequency of the ideal waveform signal. The method may additionally include generating a compensated transmission signal using the pulse compression radar system based on the adaptive frequency coefficients and the frequency sweep coefficients.

Abstract: An antenna assembly is provided that may include an antenna element having first and second opposed sides. The antenna element may be configured to transmit or receive signals of a desired wavelength. The antenna assembly may also include a first conductive surface disposed proximate the first side of the antenna element and lying in a plane substantially perpendicular to the antenna element, and a second conductive surface disposed proximate the second side of the antenna element and lying in a plane substantially perpendicular to the first antenna element. The second conductive surface may be substantially parallel to, and spaced apart from, the plane in which the first conductive surface lies. Collectively the first and second conductive surfaces may be configured to excite wave propagation modes of a higher order than a fundamental propagation mode for reception or transmission of signals of the desired wavelength by the antenna element.

Abstract: An FMCW radar system includes received signal processing arranged to apply multiple window functions in parallel to a received beat signal including at least one window function having a narrower main-lobe in its frequency response than at least one other window function and said at least one other window function having relatively higher side-lobe attenuation in its frequency response, transform the output of the multiple window functions from the time domain to the frequency domain, and combine the outputs of the transforms for further processing. Both narrow frequency resolution and thus good range discrimination, and also good side-lobe attenuation to avoid close interference are achieved.

Abstract: An antenna assembly is provided that may include an antenna element having first and second opposed sides. The antenna element may be configured to transmit or receive signals of a desired wavelength. The antenna assembly may also include a first conductive surface disposed proximate the first side of the antenna element and lying in a plane substantially perpendicular to the antenna element, and a second conductive surface disposed proximate the second side of the antenna element and lying in a plane substantially perpendicular to the first antenna element. The second conductive surface may be substantially parallel to, and spaced apart from, the plane in which the first conductive surface lies. Collectively the first and second conductive surfaces may be configured to excite wave propagation modes of a higher order than a fundamental propagation mode for reception or transmission of signals of the desired wavelength by the antenna element.

Abstract: The invention relates to a microwave pulse generator for generating microwave pulses with a pulse duration in the nanosecond range. The microwave pulse generator includes a pulse generator for generating control pulses of a constant pulse duration and a microwave oscillator generating microwave oscillations. The microwave oscillator includes a transistor amplifier, to which a frequency-determining resonant circuit and an ohmic device for reducing the resonant Q-value are connected in such a way that a control pulse of the pulse generator applied to an input terminal of the transistor amplifier causes the microwave oscillator to produce a microwave oscillation that can be tapped at an output terminal of the microwave oscillator, wherein the microwave oscillation follows at least approximately the temporal course of the control pulse.

Abstract: The invention relates to a microwave pulse generator for generating microwave pulses with a pulse duration in the nanosecond range. The microwave pulse generator includes a pulse generator for generating control pulses of a constant pulse duration and a microwave oscillator generating microwave oscillations. The microwave oscillator includes a transistor amplifier, to which a frequency-determining resonant circuit and an ohmic device for reducing the resonant Q-value are connected in such a way that a control pulse of the pulse generator applied to an input terminal of the transistor amplifier causes the microwave oscillator to produce a microwave oscillation that can be tapped at an output terminal of the microwave oscillator, wherein the microwave oscillation follows at least approximately the temporal course of the control pulse.