559 results about "Modulated continuous wave" patented technology

A three-dimensional imaging radar operating at high frequency e.g., 670 GHz radar using low phase-noise synthesizers and a fast chirper to generate a frequency-modulated continuous-wave (FMCW) waveform, is disclosed that operates with a multiplexed beam to obtain range information simultaneously on multiple pixels of a target. A source transmit beam may be divided by a hybrid coupler into multiple transmit beams multiplexed together and directed to be reflected off a target and return as a single receive beam which is demultiplexed and processed to reveal range information of separate pixels of the target associated with each transmit beam simultaneously. The multiple transmit beams may be developed with appropriate optics to be temporally and spatially differentiated before being directed to the target. Temporal differentiation corresponds to a different intermediate frequencies separating the range information of the multiple pixels. Collinear transmit beams having differentiated polarizations may also be implemented.

A system and method are provided to reduce the effect of an interfering signal in a radar return signal for a frequency modulated continuous wave (FMCW) radar. Once the interfering signal is detected, an extent of the interfering signal is determined and the data that was corrupted by the interfering signal is not included in the processing of the radar return signal. This allows the radar to detect a target in the presence of the interfering signal. The system and method can benefit any FMCW radar that is within the range of an interfering radar source (e.g. another FMCW radar, a police radar gun, a pulse radar, etc.) operating in the same frequency band as the FMCW radar. An alternative arrangement provides a system and method for determining the frequency of the interfering signal and then avoiding transmitting power in that portion of the frequency spectrum where the interfering signal is present.

A frequency modulated continuous wave (FMCW) radar system is provided that includes a receiver configured to generate a digital intermediate frequency (IF) signal, and an interference monitoring component coupled to the receiver to receive the digital IF signal, in which the interference monitoring component is configured to monitor at least one sub-band in the digital IF signal for interference, in which the at least one sub-band does not include a radar signal.

A method for frequency modulated continuous wave LADAR imaging is provided. The method comprises the steps of generating a chirped laser signal and a constant-frequency laser signal, forming a target laser signal from the chirped laser signal and the constant-frequency laser signal and forming a local oscillator laser signal from the chirped laser signal and the constant-frequency laser signal. The method further comprises delaying or frequency shifting the local oscillator laser signal and directing the target laser signal to a target. The method further comprises combining a returned signal received from the target with the delayed or frequency shifted local oscillator laser signal to form a combined received signal, and capturing the combined received signal with a plurality of image sensors. The method further comprises performing a nonlinear operation on the captured combined received signal and Fourier transforming the captured combined received signal to determine a range corresponding to each of the plurality of image sensors in the imaging device.

A FM-CW radar system comprises a frequency modulated continuous wave digital generator that produces both in-phase (I) and quadrature-phase (Q) outputs to orthogonally oriented transmitter antennas. A linearly polarized beam is output from a switched antenna array that allows a variety of I-and-Q pairs of bowtie antennas to be alternately connected to the transmitter and receiver. The receiver inputs I-and-Q signals from another bowtie antenna in the array and mixes these with samples from the transmitter. Such synchronous detection produces I-and-Q beat frequency products that are sampled by dual analog-to-digital converters (ADC's). The digital samples receive four kinds of compensation, including frequency-and-phase, wiring delay, and fast Fourier transform (FFT). The compensated samples are then digitally converted by an FFT-unit into time-domain signals. Such can then be processed conventionally for range information to the target that has returned the FM-CW echo signal.

A FM-CW radar system comprises a frequency modulated continuous wave digital generator that produces both in-phase (I) and quadrature-phase (Q) outputs to orthogonally oriented transmitter antennas. A linearly polarized beam is output from a switched antenna array that allows a variety of I-and-Q pairs of bowtie antennas to be alternately connected to the transmitter and receiver. The receiver inputs I-and-Q signals from another bowtie antenna in the array and mixes these with samples from the transmitter. Such synchronous detection produces I-and-Q beat frequency products that are sampled by dual analog-to-digital converters (ADC's). The digital samples receive four kinds of compensation, including frequency-and-phase, wiring delay, and fast Fourier transform (FFT). The compensated samples are then digitally converted by an FFT-unit into time-domain signals. Such can then be processed conventionally for range information to the target that has returned the FM-CW echo signal.

A system and method are provided to reduce an interfering signal in a radar return signal for a frequency modulated continuous wave (FMCW) radar. Once the interfering signal is detected, an extent of the interfering signal is determined and the interfering signal is removed from the radar return signal. This allows the radar to detect a target in the presence of the interfering signal. The system and method can benefit any FMCW radar that is within the range of an interfering radar source (e.g. another FMCW radar, a police radar gun, a pulse radar, etc.) operating in the same frequency band as the FMCW radar.

A back-up aid indication system includes a sensor for providing detection coverage in a predetermined coverage zone behind a vehicle. The sensor includes a transmit antenna adapted for transmitting an RF signal having a quasi-collimated antenna pattern in a near field. The system further includes a waveform generator which selectively provides one of a frequency modulated continuous wave FMCW Chirp signal and a pulse waveform signal as the transmitted RF signal.

In the proposed low complexity technique a hierarchical approach is created. An initial FFT based detection and range estimation gives a coarse range estimate of a group of objects within the Rayleigh limit or with varying sizes resulting from widely varying reflection strengths. For each group of detected peaks, demodulate the input to near DC, filter out other peaks (or other object groups) and decimate the signal to reduce the data size. Then perform super-resolution methods on this limited data size. The resulting distance estimations provide distance relative to the coarse estimation from the FFT processing.

The invention provides a millimeter wave frequency modulated continuous wave (FMCW) two-unit phased array distance and velocity measurement monolithic radar transceiver and belongs to the field of distance and velocity measurement radar transceivers. The millimeter wave FMCW two-unit phased array distance and velocity measurement monolithic radar transceiver is characterized by being formed by a FMCW transmitting module, a two-unit receiving module, a digital control module and a polarization generating module. The FMCW transmitting module is used for generating FMCW continuous-wave modulated signals, the continuous-wave modulated signals are sent out through an antenna after being amplified, the two-unit receiving module is used for processing signals reflected back from a target, the digital control module is used for controlling configurable amount in a system, sweep frequency cycle of FMCW modulation signals, sweep frequency bandwidth, signal transmitting power, gain of a receiving branch, bandwidth of a five-order Butterworth low-pass filter and phase shift value of a phase shifter can be configured, and the millimeter wave FMCW two-unit phased array distance and velocity measurement monolithic radar transceiver can be applied to detection of targets at close distance, far distance and different angles.

A wind turbine blade inspection system includes a frequency modulated continuous wave radar system configured to be movable with respect to a wind turbine blade while transmitting reference microwave signals and receiving reflected microwave signals and a processor configured for using a synthetic aperture analysis technique to obtain a focused image of at least a region of the wind turbine blade based on the reflected microwave signals.

Disclosed is a system and method for a hybrid radar system that integrates frequency-modulated continuous wave (FMCW) mode and interferometry mode. The radar works as a time division system that continuously switches between the FMCW mode and interferometry mode. The FMCW mode is responsible for absolute range detection and the interferometry mode takes cares of the weak physiological movement monitoring. The respective accuracies in range detection and displacement measurement complements the advantages of the two radar modes, providing versatile performance. By steering the antenna beam, the proposed radar system becomes an ideal solution for indoor health care, human localization, and human-computer interaction. Objects or human targets with or without stationary clutters can be precisely located. At the same time, the targets' vital signs and gestures can be monitored.

The invention discloses a multi-life monitoring system based on FMCW (frequency modulated continuous wave) wideband radar. The multi-life monitoring system comprises a transmitting unit, a receiving unit, a signal processing unit and a wireless signal transmitting unit; an FMCW signal is transmitted from the FMCW wideband radar to no less than one human object by virtue of the transmitting unit; a reflected echo signal is received by virtue of the receiving unit; the echo signal, which carries vital sign signals, is processed by virtue of the signal processing unit; the vital sign signals are demodulated and separated from the echo signal; and the vital sign signals are transmitted to a computer terminal by virtue of the wireless signal transmitting unit, so that respiration and heartbeat signals of detected persons are monitored under the condition of avoiding contact with the bodies of the detected persons. With the implementation of the multi-life monitoring system disclosed by the invention, under the circumstance of avoiding the contact of any electrodes and sensors with patients, the respiration and heart rates of the plurality of patients can be simultaneously monitored by a long time at a relatively long distance, so that the detected persons can feel more easily and comfortably; the multi-life monitoring system can be widely applied to clinical dynamic monitoring and sleep quality monitoring of patients with severe burn and the like; and meanwhile, the multi-life monitoring system can be also applied to researches in the field of psychology.

A three-dimensional imaging radar operating at high frequency e.g., 670 GHz, is disclosed. The active target illumination inherent in radar solves the problem of low signal power and narrow-band detection by using submillimeter heterodyne mixer receivers. A submillimeter imaging radar may use low phase-noise synthesizers and a fast chirper to generate a frequency-modulated continuous-wave (FMCW) waveform. Three-dimensional images are generated through range information derived for each pixel scanned over a target. A peak finding algorithm may be used in processing for each pixel to differentiate material layers of the target. Improved focusing is achieved through a compensation signal sampled from a point source calibration target and applied to received signals from active targets prior to FFT-based range compression to extract and display high-resolution target images. Such an imaging radar has particular application in detecting concealed weapons or contraband.

A sense-and-avoid system, for an unmanned air vehicle (UAV), configured to detect and estimate the relative position and velocity of a nearby object and to enable determination whether the nearby object poses a collision threat to the UAV. In one embodiment, the sense-and-avoid system is provided with a frequency modulated continuous wave (FMCW) synthesizer adapted to generate at least one swept-frequency waveform. The sense-and-avoid system may also be included with an RF subassembly. In some embodiments, the RF subassembly may include at least one transmit antenna adapted to transmit the at least one swept-frequency waveform. The at last one swept-frequency waveform may illuminate the nearby object. The sense-and-avoid system may be further provided with a plurality of receive antennas adapted to receive an echo signal from the nearby object. In some embodiments, the echo signal results from the illumination of the nearby object by the swept-frequency waveform. Additionally, the sense-and-avoid system may be provided with a signal processor configured to analyze the received echo signal and to derive object data for the nearby object. The object data may include at least range, radial velocity, and two-dimensional angle of arrival.

A micro-mirror optical tracking and ranging system comprises an optical transceiver having a Micro-Electro-Optical Mechanical System (MEOMS) micro-mirror beam steering system and an electronic control and operating system for processing electronic signals. An optical transceiver and MEOMS micro-mirror beam steering system comprises two oppositely installed micro-mirrors controlled so that they spin and tilt synchronously and project a laser beam out in a wide solid angle and interval in a substantially conically shaped scanning pattern. Such an optical transmitter system provides a steered frequency-modulated continuous-wave (FMCW) laser beam. When a laser beam waveform reflects off of an object within the scanned patter it is detected by the optical receiver an electronic control and operating system processes the detected laser beam waveform by mixing it with the original transmitted laser beam waveform and calculates the precise distance and location of the object.

Disclosed herein is a frequency modulated continuous wave (FMCW) radar device, including: a continuous wave (CW) signal generator configured to generate a transmit (Tx) CW signal; a radio frequency (RF) transmitter configured to transmit the generated Tx CW signal as an RF signal through a Tx antenna; an RF receiver configured to receive a CW signal which is reflected and returned from a forward object after the Tx CW signal is transmitted; a target detector configured to extract speed and angle using a frequency difference between the Tx CW signal and the reflected CW signal, and detect an approaching target; and a detection controller configured to control the RF transmitter to transmit the Tx CW signal as a signal having a triangular waveform in a time-frequency graph and to additionally transmit the Tx CW signal as a signal having a crossbar waveform at a predetermined frequency for a predetermined time, and extract speed and angle from the reflected CW signal having a crossbar waveform so as to detect the approaching target, when the sign of the target speed extracted from the reflected CW signal having a triangular waveform is negative (−).

A method for a radar for determining a level of interference of return of a radar wave transmitted by the radar from a target object and radio wave transmitted by some other radar, and a radar, in particular a frequency modulated continuous wave (FMCW) radar, that performs the method for determining the level of interference between the radar and some other radar is provided. In the method according to the present invention, after incident radio wave received by the radar is subjected by a frequency analysis to obtain frequency spectrum characteristic of the incident radio wave, one of frequency components of incident radio wave, the one of the frequency components having larger intensity than a predetermined intensity threshold value is not used to calculate a reference value that indicates the level of interference.

A system for small space positioning comprises a transmitting element at a fixed and known location, which transmitting a modulated continuous wave, for example an ultrasonic wave, having a continuous carrier signal part and a base-band signal modulated thereon. The transmitting element transmits the modulated continuous wave over a range in which an object to be positioned may appear. A receiving element receives signals transmitted by the transmitting device and reflected by the object, and a position detection element determines a position of the object from analysis of both the carrier signal part and the base-band signal received from the reflected signal.

An inventive frequency modulated continuous wave (FMCW) radar system realizes both a quick detection of a higher relative speed provisional target and a sure detection of a smaller relative speed provisional target. The number of detection cycles used for a paring validity check, used to see if a detected target or a pair of frequencies is an actual target or a pair for an actual target, is set in response to the relative velocity enabling the target information for a target of higher relative velocity to be output more quickly.

The invention relates to an automobile anticollision radar system based on frequency-modulated continuous wave (FMCW) and belongs to the technical field of automobile protection. The system can measure the distance and velocity of a target and effectively avoid car crashes. The system comprises the following components: a radar sensor, a filter, an automatic gain control amplifier, an analog-to-digital converter, a digital signal processor and a corresponding early-warning device. The radar sensor collects signals including leaked modulation, intermediate-frequency and high-frequency signals; the filter filters off the leaked modulation waves and high-frequency component; in the digital signal processor, the spectral analysis is performed by means of FFT and the frequency measurement results are converted into distance information and velocity information; and different warning modes are adopted according to the measurement results. The maximum acceptance range of the system can reach 150 m, the distance discrimination is 1 m, the velocity discrimination is 1 m / s, and the working environment is -40 DEG C to -80 DEG C.

A micro-mirror optical tracking and ranging system comprises an optical transceiver having a Micro-Electro-Optical Mechanical System (MEOMS) micro-mirror beam steering system and an electronic control and operating system for processing electronic signals. An optical transceiver and MEOMS micro-mirror beam steering system comprises two oppositely installed micro-mirrors controlled so that they spin and tilt synchronously and project a laser beam out in a wide solid angle and interval in a substantially conically shaped scanning pattern. Such an optical transmitter system provides a steered frequency-modulated continuous-wave (FMCW) laser beam. When a laser beam waveform reflects off of an object within the scanned patter it is detected by the optical receiver an electronic control and operating system processes the detected laser beam waveform by mixing it with the original transmitted laser beam waveform and calculates the precise distance and location of the object.

A method for the linearization of frequency modulated continuous wave (FMCW) radar devices having non-linear, ramp-shaped, modulated transmitter frequency progression x(t). With this invention, a correction phase term for compensation of the phase error in the reception signal q(t) is calculated on the receiver side in this device.

The invention provides a linear frequency modulation continuous wave radar distance measuring method. According to the method, a discrete Fourier frequency spectrum curve of an intermediate frequency signal is fitted through interpolation to find out a frequency value corresponding to a spectral line number with th maximum value on the frequency spectrum; the frequency value is much closer to the theoretical frequency value. Accordingly, the method is capable of reducing error caused by picket fence effect and greatly improving precision of FMCW (Frequency Modulated Continuous Wave) distance measurement. In addition, the method is capable of mainly concentrating white noise frequency spectrum curves, which are distributed evenly, in a high frequency band through discrete Fourier transform; the frequency of middle-band signal is in a low-frequency band; a frequency spectrum of a high-frequency band has less influence on the frequency spectrum of the low-frequency band, so that the method does not have great influence on calculation precision under a certain noise influence, thus ensuring the reliability of the calculation result.

A FM-CW radar system comprises a frequency modulated continuous wave digital generator that produces both in-phase (I) and quadrature-phase (Q) outputs to orthogonally oriented transmitter antennas. A linearly polarized beam is output from a switched antenna array that allows a variety of I-and-Q pairs of bowtie antennas to be alternately connected to the transmitter and receiver. The receiver inputs I-and-Q signals from another bowtie antenna in the array and mixes these with samples from the transmitter. Such synchronous detection produces I-and-Q beat frequency products that are sampled by dual analog-to-digital converters (ADC's). The digital samples receive four kinds of compensation, including frequency-and-phase, wiring delay, and fast Fourier transform (FFT). The compensated samples are then digitally converted by an FFT-unit into time-domain signals. Such can then be processed conventionally for range information to the target that has returned the FM-CW echo signal.

The invention discloses a small FMCW-based (frequency modulated continuous wave) SAR (synthetic aperture radar) imaging system by using an FPGA (field programmable gate array) to mainly overcome the disadvantages of large volume, heavy weight and high power consumption of the traditional SAR imaging system. The small FMCW-based SAR imaging system comprises a radar front end, an acquisition preprocessing unit, a signal processing unit and a receiving host, wherein the acquisition preprocessing unit comprises an instruction communication module, an A / D (analogue / digital) acquisition module, an FPGA control and calculation module and a data sending interface; the signal processing unit comprises a data receiving interface, an FPGA control module, a DSP (digital signal processor) calculation module and a data sending interface; the acquisition preprocessing unit and the FPGA of the signal processing unit are used for receiving back waves and inertial navigation parameters of the radar front end, feeding back the regulation instruction to the radar front end to perform distance pulse pressure, transmitting data to a DSP, receiving the calculation results of the DSP and transmitting thecalculation results of the DSP to the receiving host for display. According to the small FMCW-based SAR imaging system, one picture can be imaged in real time in one second under the airborne condition, the small FMCW-based SAR imaging system has the advantages of small size, light weight, small power consumption and good reliability and can be applied to the fields of radars, guided missile, remote sensing, etc.

The invention relates to an automobile active anti-collision radar based on pseudorandom code and linear frequency modulated continuous wave, belonging to the field of automobile radar, comprising a pseudorandom code and linear frequency modulated control signal generator, a pseudorandom code and linear frequency modulated continuous wave emitter, a sending antenna, a receiving antenna, a low-noise amplification mixed frequency receiving channel, a linear frequency modulated signal processing and pseudorandom code multi-path parallel correlation processor, a parallel data processor and an executing terminal. The pseudorandom code is used for modulating the phase of radar carrier wave and performing linear frequency modulation to the radar carrier wave so as to form a double-modulation emitting signal. Two systems are combined, so that the inhibition ability of interference echo is improved; the false alarm caused by false targets is removed; different codes of different automobile radars are achieved; the interference caused by the automobile radar is removed; the detection ability of the active anti-collision radar is improved; the false alarm rate is improved; and the inhibitionability under complex road condition is good.

The invention discloses an SAR (synthetic aperture radar) real-time imaging method based on a frequency modulated continuous wave, and the problem that a conventional method cannot process the real-time echo data of the frequency modulated continuous wave is mainly solved. The SAR real-time imaging method comprises the following realization steps of: carrying out previous wave filtration on initial data; carrying out Doppler center estimation, walking correction and Doppler center translation on the data subjected to the previous wave filtration; carrying out inverse fast Fourier transform (IFFT) on the data subjected to the center translation along a distance direction; carrying out Doppler frequency modulation rate estimation on the data subjected to the IFFT to obtain a frequency modulation rate value; calculating the motion error parameter of a loader according to the frequency modulation rate value; carrying out motion compensation on the data subjected to the previous wave filtration according to the motion error parameter; carrying out the walking correction, the Doppler center translation and bending correction on the data subjected to the motion compensation; carrying outthe frequency modulation rate estimation on the data subjected to the bending correction; and carrying out focusing and imaging on the data along an azimuth direction according to the obtained frequency modulation rate value to obtain an SAR image. The SAR real-time imaging method has the advantage that the SAR imaging resolution is high, and can be applied to the processing of the real-time echodata of the frequency modulated continuous wave.

A system and method are provided to reduce the effect of an interfering signal in a radar return signal for a frequency modulated continuous wave (FMCW) radar. Once the interfering signal is detected, an extent of the interfering signal is determined and the data that was corrupted by the interfering signal is not included in the processing of the radar return signal. This allows the radar to detect a target in the presence of the interfering signal. The system and method can benefit any FMCW radar that is within the range of an interfering radar source (e.g. another FMCW radar, a police radar gun, a pulse radar, etc.) operating in the same frequency band as the FMCW radar. An alternative arrangement provides a system and method for determining the frequency of the interfering signal and then avoiding transmitting power in that portion of the frequency spectrum where the interfering signal is present.

The system and method for radar calibration using antenna leakage is a simplified means of calibrating the channels in amplitude and phase using natural signal leakage between antennas. It utilizes as calibration signal a wideband sinusoidal Frequency Modulated Continuous Wave (FMCW) waveform with a modulation index and modulation frequency chosen to generate spectral components (or discrete signal frequencies) that fall within the receiver Doppler passband of the radar. The calibration signal is radiated out of the transmitting antenna and enters the radar receiver front-end through the transmit-to-receive antenna leakage which occurs naturally. This technique provides a low-complexity (simpler hardware realization) means for achieving a wideband calibration rapidly and is a practical alternative to the conventional calibration approach that relies on generating offset Doppler signals that are coupled into the radar receiver front-end through the use of couplers and cabling within the radar.