Abstract: The present invention relates to an active radar system and a corresponding method. The proposed system comprises at least two transmit antennas that each transmits radiation to a scene as a transmit signal, said transmit signal comprising a series of frequency modulated pulses, at least one receive antenna that receives radiation from said scene as a receive signal, a controller that controls said at least two transmit antennas. The transmissions of the transmit signals are subsequently initiated with time offsets, controlled to be larger than the time delay between transmission of a first transmit signal of said two transmit signals and reception of radiation of said first transmit signal by said at least one receive antenna and to be smaller than the time duration of a complete frequency modulated pulse of said first transmit signal.

Abstract: An antenna architecture for hemispherically-scanning active electronically scanned arrays (AESA). The antenna architecture utilizes variable diameter disks of antenna elements configured in a conical implementation. The antenna elements are oriented such that the element boresight is normal to the surface of the conical structure. Beamforming takes place on each disk first, and them separately in combining the signals from each disk, thereby reducing complexity. The antenna optionally utilizes disks of antenna elements of the same diameter to form a cylindrical antenna, which when combined with a conical configuration create enhanced sectors while maintaining a hemispherical coverage capability. Further, use of two conical configurations can produce a fully spherical coverage capability.

Abstract: A signal generation system suitable for use in a radar system comprises a local oscillator (LO) and an intermediate frequency (IF) oscillator, wherein the IF oscillator is a Direct Digital Synthesizer (DDS), and the LO is a free running oscillator not itself locked to another oscillator but which acts as a clock reference for the DDS and is the highest frequency oscillator in the system. The LO may also act as a reference for a receive chain digitizer. The invention exploits phase noise advantages of a free running oscillator at some distance from the carrier whilst maintaining coherency with other system components. The system typically finds application in FMCW radars.

Abstract: Device for transmitting/receiving frequency modulated type radar waves that includes: a circuit for generating radar waves which includes a voltage-controlled oscillator coupled to a circulator which is itself connected to a transmit/receive antenna; a detection circuit including a first mixer which is fed by the circulator and the voltage-controlled oscillator, wherein voltage-controlled oscillator incluing an input for injecting a signal generated by an additional circuit, the additional circuit having its input fed by the output signal of voltage-controlled oscillator and including a second mixer which is fed by two signals generated on the basis of the output signal of voltage-controlled oscillator.

Abstract: A radar system including a switching mode power converter. A pulse radar unit is configured to transmit RF pulses with a pulse repetition frequency. The power converter includes a switching controller that is configured to control at least one switching element. The switching controller is configured to receive a frequency modulated input signal. The modulation frequency of the input signal is configured to be derived from the pulse repetition frequency of the radar unit.

Abstract: An integrated circuit for phase shifting a radio frequency signal, wherein the integrated circuit comprises at least one phase shifter comprising: at least one input for receiving a radio frequency signal, a voltage variable element; and a plurality of active devices operably coupled to the voltage variable element and arranged to receive a variable control voltage. The plurality of active devices comprise at least two active devices coupled in a common base arrangement and arranged to receive the radio frequency signal with the voltage variable element coupling the emitter contacts or source contacts of the at least two active devices, such that a variable control voltage applied to the voltage variable element adjusts a phase of the radio frequency signal.

Abstract: In order to prevent delays in output of detection results, even when a plurality of frequency modulation methods with different frequency change rates are used, an FM-CW radar device employing frequency modulation with two different frequency change rates, has distance/velocity detection unit for detecting the relative distance or relative velocity of a target object based on beat signals of transmission signals with the same frequency change rate and for detecting the relative distance or relative velocity using beat signals when the frequency change rates are different, and distance/velocity confirmation unit for adding evaluation values for relative distances or relative velocities detected in the detection processing, and for confirming the relative distance or relative velocity based on the evaluation value which has reached a criterion value. As a result, more data can be obtained in one detection cycle, and the same advantageous results as when executing a plurality of detection cycles can be obtained.

Abstract: An FMCW radar sensor for motor vehicles, having a high frequency part for generating, transmitting and receiving radar signals, a modulation device for controlling the frequency modulation of the transmitted radar signal, at least one analog preprocessing stage for an intermediate frequency signal formed from the received radar signal, at least one analog/digital transducer stage, and a processor for controlling the modulation device and for further processing the digital signals of the analog/digital transducer stage, wherein the modulation device, the preprocessing stage and the analog/digital transducer stage are integrated into a single semiconductor component, which also has a monitoring device and registers for the configuration and monitoring of the components of the semiconductor component as well as an interface to the processor.

Abstract: In the method for detecting precipitation using a radar sensor, the radar sensor emits a transmission signal, whose frequency is varied periodically in successive modulation ramps. Signals received by the radar sensor are analyzed to determine precipitation on the basis of two different criteria. In the method, a first criterion relates to signals which are received during a pass-through of a modulation ramp, and a second criterion relates to a comparison of signals which are received during a pass-through of at least two successive modulation ramps.

Abstract: An integrated circuit comprises frequency generation circuitry for controlling a frequency source for an automotive radar system. The frequency generation circuitry comprises a Phase Locked Loop (PLL) arranged to generate a control signal for controlling the frequency source, a fractional-N divider located within a feedback loop of the PLL, and frequency pattern control logic operably coupled to the fractional-N divider and arranged to control the fractional-N divider, by way of a frequency control signal, such that the PLL generates a Frequency Modulated Continuous Wave (FMCW) control signal.

Abstract: According to one embodiment, an FMCW signal generation circuit includes a voltage-controlled oscillator, a digital phase detector, a differentiator, a comparator, a low-pass filter, an amplifier, a D/A converter, and an integrator. The voltage-controlled oscillator generates an FMCW signal including an oscillation frequency corresponding to a control signal. The digital phase detector detects phase information of the FMCW signal to generate a detection signal. The differentiator differentiates the detection signal once to generate a differential signal. The comparator compares the differential signal with a target frequency to generate an error signal. The low-pass filter suppresses a high-frequency component of the error signal to generate a filtered signal. The amplifier amplifies the filtered signal to generate an amplified signal. The D/A converter converts the amplified signal to analog to generate an analog signal. The integrator integrates the analog signal to generate the control signal.

Abstract: A communication unit comprises a controller and a radio frequency signal path having a plurality of delay elements operably coupled to a series of respective amplifier stages, wherein the controller is arranged to individually enable the respective amplifier stages. In response thereto a number of the plurality of delay elements are selectively inserted into or by-passed from the radio frequency signal path thereby adjusting a phase shift applied to signals provided through the radio frequency signal path.

Abstract: The invention relates to a device for generation of microwaves comprising a virtual cathode oscillator (1) in a coaxial embodiment with an outer cylindrical tube forming a cathode (2) and connected to a transmission line (14) for feeding the cathode (2) with voltage pulses, and an inner cylindrical tube, at least partially transparent for electrons, forming a anode (3) and connected to a waveguide (13) for outputting microwave radiation generated by the formation of a virtual cathode (4) inside an area enclosed by the anode. Through the introduction of electrically conductive structures (5 and 6) a device for generation of microwaves is achieved that demonstrates higher efficiency and higher peak output.

Abstract: A radar system is disclosed, which comprises an orthogonal frequency division multiplexing (OFDM) modem and a frequency scanning antenna. In transmit, the OFDM modem modulates radar waveforms and the frequency scanning antenna radiates the OFDM modulated radio frequency (RF) energy. In receive mode, the frequency scanning antenna captures the echoes and the OFDM modem demodulates the echoes. Directionality of the frequency scanning antenna is dependent upon RF carrier frequency. In other features, the radar system further comprises a transmit/receive (T/R) module that up-converts and amplifies the OFDM modulation, and outputs the amplified signal to the frequency scanning antenna. The T/R module amplifies and down-converts a received RF echo from the frequency scanning antenna and outputs the down-converted echo to the OFDM modem. A plurality of scanning angles are measured simultaneously.

Abstract: An FMCW radar has a variable frequency microwave signal source for outputting a microwave signal, a frequency divider, a phase-locked loop, a loop filter and a reference signal source. The frequency divider is connected between the output of the variable frequency microwave signal source and an input of the phase-locked loop. The loop filter is connected between the output of the phase-locked loop and the input of the variable frequency microwave signal source. The reference signal source is connected to an additional input of the phase-locked loop. The frequency divider is adjustable, in particular digitally adjustable. A method for operating an FMWC radar includes adjusting a variable frequency microwave signal source by way of a closed-loop control circuit which uses a reference signal of a reference signal source, especially of a quartz oscillator, as the reference value, and a frequency-divided output signal of the microwave signal source as the feedback value.

Abstract: A method for lessening disturbances of a measurement signal in a radar unit for distance measurement by means of frequency-modulated radar in continuous wave operation. The method comprises steps of: registering, in a reference measurement, a reference signal as a function of time; deriving an error correction signal from the registered reference signal, wherein the error correction signal predominantly comprises spectral components caused or influenced by device-specific defects of the radar unit; registering a measurement signal; and correcting the measurement signal in accordance with the error correction signal by means of digital signal processing.

Abstract: The invention relates to a device for generation of microwaves comprising a virtual cathode oscillator (1) in a coaxial embodiment with an outer cylindrical tube forming a cathode (2) and connected to a transmission line (14) for feeding the cathode (2) with voltage pulses, and an inner cylindrical tube, at least partially transparent for electrons, forming a anode (3) and connected to a waveguide (13) for outputting microwave radiation generated by the formation of a virtual cathode (4) inside an area enclosed by the anode. Through the introduction of electrically conductive structures (5 and 6) a device for generation of microwaves is achieved that demonstrates higher efficiency and higher peak output.

Abstract: The present invention is directed to an integrated circuit device that includes a primary signal synthesizer configured to generate a free-running first digital frequency signal and at least one secondary signal synthesizer disposed in parallel with the primary signal synthesizer and configured to generate a free-running at least one second digital frequency signal. A switch element includes a first switch input coupled to the primary signal synthesizer and at least one second switch input coupled to the at least one secondary signal synthesizer. The switch element is configured to select a switch output that provides either the free-running first digital frequency signal or the free-running at least one second digital frequency signal based on a switch control input.

Abstract: This radar device includes: a transmitter to transmit a transmitting signal whose frequency is periodically increased/decreased at a predetermined rate of change; a mixer to generate a beat signal by multiplying a received signal being transmitted by the transmitter and reflected back from an object to be detected and the transmitting signal; a frequency detector to detect a frequency of the beat signal; and a controller to control the rate of change of the frequency of the transmitting signal so that the frequency of the beat signal detected by the frequency detector becomes equal to or larger than a cut-off frequency of a flicker noise caused by the mixer.

Abstract: A method and a device for the spatially resolved detection and reconstruction of objects using microwaves is described, in which at least one object to be detected is subjected to microwaves that are generated by a plurality of microwave antennas and microwave fractions reflected by the object are detected and converted into microwave signals that can be analyzed, based on which an analysis for the spatially resolved object detection is carried out.

Abstract: One embodiment of the present invention relates to a method for detecting a range and velocity of a target. In this method, an electromagnetic wave is transmitted over a frequency range, where a period of the wave comprises a number of consecutive ramps. A first ramp in the period is transmitted over a first portion of the frequency range, and a second ramp in the period is transmitted over a second portion of the frequency range that differs from the first portion. The second ramp is offset by a frequency shift relative to the first ramp. A scattered wave is received from the target and processed to determine the range and the velocity of the target. Other methods and systems are also disclosed.

Abstract: A beat signal normalizing section in a correction control section normalizes a group of sampling data of an input beat signal in one processing group. A phase amount measuring section calculates an amount of phase change of each sampling data. A correction control value calculating section compares the actually measured amount of phase change of each sampling data with an ideal amount of phase change of each sampling data and generates correction voltage data such that the actually measured amount of phase change matches with the ideal amount of phase change. Correction control data provided as the correction voltage data at each sampling time is applied to a transmission control section. The transmission control section generates transmission control data based on the correction control data and applies the transmission control data to a VCO through a DAC.

Abstract: A radar device includes: a signal processor that receives an FMCW signal, detects a peak of a beat signal according to a reception signal and a transmission signal, and performs a correspondence of the beat frequency and an angle measurement process to generate target information; a beat frequency tracking filter that receives the beat frequency and updates a position and a velocity of the target; a pair observation value tracking filter that receives the observation value of the position and the velocity of the target to update the position and the velocity of the target; an integration/selection unit that integrates the tracks of both the tracking filters together or selects one thereof; a system track memory; and an abnormal value determination unit.

Abstract: An active imaging system for imaging a target is described. The system includes a transmitting unit, a receiving unit, an antenna arrangement coupled to the transmitting unit and/or the receiving unit via a front end unit, and an image processing unit coupled to the receiving unit. The system also includes a control system coupled to the transmitting unit, the receiving unit and/or the image processing unit for controlling operation thereof. The antenna arrangement includes at least one rotating antenna synthetically forming a circular antenna. The image processing unit is configured for creating an image of the object by employing a synthetic aperture radar imaging algorithm.

Abstract: An FMCW signal generation circuit includes: an oscillator configured to oscillate in an oscillation frequency that is variable in accordance with a control signal being input thereto and output an FMCW signal having the oscillation frequency; a phase detector configured to detect a phase of the FMCW signal; a first differentiator configured to obtain a frequency by differentiating the phase detected by the phase detector; a second differentiator configured to obtain a frequency variation rate by differentiating the frequency obtained by the first differentiator; a subtractor configured to calculate an error between a set frequency variation rate that is set at a given value and the frequency variation rate obtained by the second differentiator; and an integrator configured to generate the control signal for controlling the oscillation frequency of the oscillator by integrating the error calculated by the subtractor.

Abstract: In a sensor and a radar for measuring the distance and the moving speed of a target by radiating a radio frequency, particularly a millimeter wave, compatibility between cost reduction and high detection performance has been conventionally a significant problem. In the present invention, the frequency of a transmitted signal changes during a fixed time while performing digitally-frequency-modulation on frequency sweeping straight lines extending, with different slopes relative to the time axis, from plural slightly different initial values serving as starting points, the signal is transmitted after being modulated so as to periodically repeat the sweep time serving as a unit, signal components corresponding to the respective sweeping slopes are digitally sampled, in synchronization with the transmitted modulation signal, from a received signal which is reflected and returned from a target, and the received signal is analyzed.

Abstract: The invention relates to an FMCW radar system and a method of operating an FMCW radar system to produce a linear frequency ramp. The FMCW radar system includes a VCO, a frequency divider coupled to the VCO output, followed by an A/D converter. A down-converter shifts the digitally converted signal to baseband samples, followed by a low-pass filter coupled to an output thereof. A VCO frequency estimator produces instantaneous VCO frequency estimates from phase differences determined from the filtered baseband samples. A D/A converter coupled to an output of the VCO frequency estimator produces an input signal for the VCO to produce therewith a linear VCO frequency ramp. A ?-? modulator is coupled between the VCO frequency estimator and the input of the D/A converter to produce a dithered VCO control signal, thereby increasing the effective number of bits of the D/A converter.

Abstract: Generation of electromagnetic or other waves of any frequency, coherence, modulation, power, etc. and for scaling such waves in frequency by any factor. Generation is achieved by incorporating an available source of desired coherence, modulation and power properties at some band of frequencies and scaling to the desired frequencies. For scaling, a continuously varied frequency selection mechanism, which results in source-distance dependent frequency scaling as described in copending applications titled “Passive distance measurement using spectral phase gradients” and “Distance-dependent spectra with uniform sampling spectrometry”, is combined with a means of determination, or prior knowledge, of the source distance. This distance, from the source to the frequency scaling mechanism, may be shortened with a refractive or dispersive medium, or varied for fine tuning of the frequency scale factor, and this variation may be effected via electrooptic or magnetooptic properties of the medium.

Abstract: A signal generation system suitable for use in a radar system comprises a local oscillator (LO) and an intermediate frequency (IF) oscillator, wherein the IF oscillator is a Direct Digital Synthesiser (DDS), and the LO is a free running oscillator not itself locked to another oscillator but which acts as a clock reference for the DDS and is the highest frequency oscillator in the system. The LO may also act as a reference for a receive chain digitiser. The invention exploits phase noise advantages of a free running oscillator at some distance from the carrier whilst maintaining coherency with other system components. The system typically finds application in FMCW radars.

Abstract: It is possible to generate D/A conversion voltage in which an error generated by numeric irregularities of a D/A conversion element such as resistor constituting a D/A converter 11 is corrected. A waveform generation method characterized in that input data into a D/A converter 11 are provided to the D/A converter in order at a timing at which a voltage of a desired waveform which has D/A conversion data indicating a conversion amount of the input data obtained by varying the input data by a minimum conversion unit or a unit obtained by multiplying the minimum conversion unit by an integer, and which varies with time series, becomes substantially equal to a D/A-converted voltage, whereby the D/A-converted voltage is generated in accordance with the desired waveform.

Abstract: A radar apparatus is provided. An antenna is configured to transmit a frequency-modulated transmission wave toward an object and receive a reception wave from the object. A mixer is configured to mix the transmission wave with the reception wave to generate a beat signal having a first beat interval and a second beat interval. A detecting section is configured to detect a plurality of first peak signals contained in the first beat interval of the beat signal and a plurality of second peak signals contained in the second beat interval. A grouping section is configured to group the second peak signals. A searching section is configured to search a part of the first peak signals corresponding to the grouped second peak signals. A separating section is configured to separate the part of the first peak signals from the other part of the first peak signals.

Abstract: An antenna system comprising an array of antenna elements, the array comprising a plurality of groups of antenna elements wherein each group comprises one or more antenna elements arranged in series, and wherein the system further comprises first phase-control means for performing the function of introducing respective phase-shifts to transmitted or received signals passed to or received from each of said groups to provide beamforming and second phase-control means for performing said function with respect to a sub-set of said groups. An antenna system of the invention allows two radar beam patterns having different spatial characteristics to be generated using a single antenna system. The invention also provides a radar system incorporating an antenna system of the invention.

Abstract: An FMCW radar sensor having a plurality of antenna elements and a supply circuit for supplying transmission signals having ramp-shaped modulated frequencies to the antenna elements, including a switchover device for switching over the supply circuit between a near-field mode, in which the transmission signals supplied to the individual antenna elements have a certain frequency offset, and a far-field mode, in which the frequencies of the transmission signals are identical.

Abstract: An FMCW radar has a variable frequency microwave signal source for outputting a microwave signal, a frequency divider, a phase-locked loop, a loop filter and a reference signal source. The frequency divider is connected between the output of the variable frequency microwave signal source and an input of the phase-locked loop. The loop filter is connected between the output of the phase-locked loop and the input of the variable frequency microwave signal source. The reference signal source is connected to an additional input of the phase-locked loop. The frequency divider is adjustable, in particular digitally adjustable. A method for operating an FMWC radar includes adjusting a variable frequency microwave signal source by way of a closed-loop control circuit which uses a reference signal of a reference signal source, especially of a quartz oscillator, as the reference value, and a frequency-divided output signal of the microwave signal source as the feedback value.

Abstract: A radar apparatus includes a PN code generator for generating a PN code, a variable delay device for delaying the PN code, an oscillator for generating a high-frequency signal, a transmission frequency multiplier for multiplying a frequency of a transmission differential signal obtained by being divided from the high-frequency signal by 3, a reception frequency multiplier for multiplying a frequency of a reception differential signal obtained by being divided from the high-frequency by 3, a transmitter for generating a radar wave by using the differential signal obtained through the multiplication by the transmission frequency multiplier and the PN code generated by the PN code generator, and a receiver for generating an in-phase signal and a quadrature signal from a reflected wave by using the differential signal obtained through the multiplication by the reception frequency multiplier and the PN code delayed by the delay device.

Abstract: One aspect of this disclosure relates to a method for processing a received, modulated radar pulse to resolve a radar target from noise or other targets. According to an embodiment of the method, a radar return signal is received and samples of the radar return signal are obtained. A minimum mean-square error (MMSE) pulse compression filter is determined for each successive sample. The MMSE filter is separated into a number of components using contiguous blocking, where each component includes a piecewise MMSE pulse compression filter segment. An estimate of radar range profile is obtained from an initialization stage or a previous stage. The piecewise MMSE pulse compression filter segments are applied to improve accuracy of the estimate. The estimate is repeated for two or three stages to adaptively suppress range sidelobes to a level of a noise floor. Other aspects and embodiments are provided herein.

Abstract: A beat signal normalizing section in a correction control section normalizes a group of sampling data of an input beat signal in one processing group. A phase amount measuring section calculates an amount of phase change of each sampling data. A correction control value calculating section compares the actually measured amount of phase change of each sampling data with an ideal amount of phase change of each sampling data and generates correction voltage data such that the actually measured amount of phase change matches with the ideal amount of phase change. Correction control data provided as the correction voltage data at each sampling time is applied to a transmission control section. The transmission control section generates transmission control data based on the correction control data and applies the transmission control data to a VCO through a DAC.

Abstract: Methods and systems for estimating and correcting airborne radar antenna pointing errors. The methods and systems include predicting expected received power from at least one scattering source using terrain elevation information, transmitting a radar signal to the at least one scattering source, measuring received power from the at least one scattering source, determining an antenna pointing error based on the predicted and measured received power, and adjusting an antenna angle, an input value, or other components based on the determined antenna pointing error. The methods and systems also include a radar processing and control unit for predicting expected received power from at least one scattering source using a model of the radar power measurement process that includes terrain elevation information, for measuring received power from the at least one scattering source, and for determining antenna pointing error based on the predicted and measured received power.

Abstract: The invention relates to a small and low-voltage operable dielectric waveguide device. First and second electrode are embedded in a dielectric part and are formed to be thinner than a skin depth for a frequency of electromagnetic wave propagating along a first dielectric part included in the dielectric part. Thereby, even if the first and second electrodes are arranged to be in contact with the first dielectric part, the propagating electromagnetic wave can transmit the first and second electrodes, and therefore the electromagnetic wave can propagate without being cut off and there is no influence on waveguide modes of the electromagnetic wave. Further, in a state where a transmission loss due to the embedded of the electrode is suppressed, an electric field with large electric field strength can be applied to the first dielectric part by the first and second electrodes, and a small and low-voltage operable dielectric waveguide device can be achieved.

Abstract: A designated function or “golden” slot for implementing and managing re-configurable SDR modules is provided. In an embodiment, the slot includes at least one radio frequency (RF) front end for providing an interface with at least one antenna. In addition, the slot may include at least one slot modem coupled to the RF front end for implementing at least one designated function and at least one input/output (I/O) module coupled to the slot modem. The designated function or “golden” slot is capable of implementing and managing the at least one designated function in a re-configurable module during standard and emergency operations.

Abstract: It is possible to generate D/A conversion voltage in which an error generated by numeric irregularities of a D/A conversion element such as resistor constituting a D/A converter 11 is corrected. A waveform generation method characterized in that input data into a D/A converter 11 are provided to the D/A converter in order at a timing at which a voltage of a desired waveform which has D/A conversion data indicating a conversion amount of the input data obtained by varying the input data by a minimum conversion unit or a unit obtained by multiplying the minimum conversion unit by an integer, and which varies with time series, becomes substantially equal to a D/A-converted voltage, whereby the D/A-converted voltage is generated in accordance with the desired waveform.

Abstract: A method and apparatus is operative for multiple target detection in a radar system which employs a radar waveform of two or more frequency diverse subpulses. The apparatus adds coherent processing of the subpulse echo signals to determine the presence of multiple scattering centers within the radar resolution cell. The subpulses are coherently combined and one can then estimate the number of scattering centers by forming a sample covariance matrix between the subpulse frequency channels and then performing an Eigenvalue decomposition. The resulting Eigenvalues represent the signal strengths of the scattering centers when the associated Eigenvectors correspond to the optimal subpulse weights associated with that signal. A single strong Eigenvalue indicates a single target while two or more strong Eigenvalues or those Eigenvalues larger than the noise related Eigenvalues or a threshold, indicates the presence of multiple targets.

Abstract: The invention relates to a method and system for determining a physical property for determining physical property as a function of position, where a data series is obtained by FMCW. The data series comprises data points from one or more channels and the method comprises measuring a number of data points corresponding to Nda different values of frequency of modulation, performing one or more processing step comprising at least part of said primary data series to obtain at least one secondary data series comprising N (N>Nda) data points for the values of frequency of modulation, performing a transformation of said secondary data series from frequency domain to obtain at least one back scattering curve in space domain and optionally said back scattering curve(s) to one or more physical properties as a function of position.

Abstract: Disclosed is a method of bias adjustment for a millimeter wave radar apparatus that can efficiently and highly accurately adjust the bias of an MMIC used in a radio frequency circuit in the millimeter wave radar apparatus.

Abstract: A radar system is disclosed, which comprises an orthogonal frequency division multiplexing (OFDM) modem and a frequency scanning antenna. In transmit, the OFDM modem modulates radar waveforms and the frequency scanning antenna radiates the OFDM modulated radio frequency (RF) energy. In receive mode, the frequency scanning antenna captures the echoes and the OFDM modem demodulates the echoes. Directionality of the frequency scanning antenna is dependent upon RF carrier frequency. In other features, the radar system further comprises a transmit/receive (T/R) module that up-converts and amplifies the OFDM modulation, and outputs the amplified signal to the frequency scanning antenna. The T/R module amplifies and down-converts a received RF echo from the frequency scanning antenna and outputs the down-converted echo to the OFDM modem. A plurality of scanning angles are measured simultaneously.

Abstract: A radar apparatus includes a PN code generator for generating a PN code, a variable delay device for delaying the PN code, an oscillator for generating a high-frequency signal, a transmission frequency multiplier for multiplying a frequency of a transmission differential signal obtained by being divided from the high-frequency signal by 3, a reception frequency multiplier for multiplying a frequency of a reception differential signal obtained by being divided from the high-frequency by 3, a transmitter for generating a radar wave by using the differential signal obtained through the multiplication by the transmission frequency multiplier and the PN code generated by the PN code generator, and a receiver for generating an in-phase signal and a quadrature signal from a reflected wave by using the differential signal obtained through the multiplication by the reception frequency multiplier and the PN code delayed by the delay device.

Abstract: The invention relates to an FMCW radar system and a method of operating an FMCW radar system to produce a linear frequency ramp. The FMCW radar system includes a VCO, a frequency divider coupled to the VCO output, followed by an A/D converter. A down-converter shifts the digitally converted signal to baseband samples, followed by a low-pass filter coupled to an output thereof. A VCO frequency estimator produces instantaneous VCO frequency estimates from phase differences determined from the filtered baseband samples. A D/A converter coupled to an output of the VCO frequency estimator produces an input signal for the VCO to produce therewith a linear VCO frequency ramp. A ?-? modulator is coupled between the VCO frequency estimator and the input of the D/A converter to produce a dithered VCO control signal, thereby increasing the effective number of bits of the D/A converter.

Abstract: An embedded calibration mechanism and method for a time-of-flight ranging system. The calibration mechanism (200) comprises a channel (202) having known characteristics. Periodically or as part of a calibration function, a pulse is transmitted through the calibration channel (202) and parameters such transmit pulse delay time and apparent velocity are determined. The calibration parameters or measurements are used to calibrate or compensate operation or measurements from the measurement channel.

Abstract: A mixer circuit includes: a rat race circuit including a ring-shaped transmission line with a first terminal, a second terminal, a third terminal, and a fourth terminal, the first to fourth terminals being disposed, in that order, clockwise along the transmission line and equally spaced ?LO/4 from one another, except that the first terminal is spaced 3*?LO/4 from the fourth terminal, where ?LO is the wavelength of the LO signal applied to the mixer circuit; an LO terminal connected to the first terminal; a first diode and a second diode connected in the same polarity to the second terminal and the fourth terminal, respectively; and an RF terminal and an IF terminal both connected to the third terminal. The frequency of the LO signal is one-half of the frequency of the RF signal applied to the mixer circuit.

Abstract: A transmit-receive FM-CW radar apparatus according to one mode of the invention comprises: a mixer for downconverting an IF signal; a switch provided on the input side of the mixer; and a switch controller for controlling the switch on and off in different modes and selecting the IF signal in the different modes for supply to said mixer. A transmit-receive FM-CW radar apparatus according to another mode of the invention comprises: a mixer for downconverting an IF signal; a switch for turning on and off a local signal to be supplied to the mixer; and a switch controller for controlling the switch on and off in different modes and selecting the local signal in the different modes for supply to the mixer.