Abstract: Methods for tracking a signal origin by a spectrum analysis and management device are disclosed. Signal characteristics of other known emitters are used for obtaining a position of an emitter of a signal of interest. In one embodiment, frequency difference of arrival technique is implemented. In another embodiment, time difference of arrival technique is implemented.

Abstract: Apparatus and methods for identifying a wireless signal-emitting device are disclosed. The apparatus is configured to sense and measure wireless communication signals from signal-emitting devices in a spectrum. The apparatus is operable to automatically detect a signal of interest from the wireless signal-emitting device and create a signal profile of the signal of interest; compare the signal profile with stored device signal profiles for identification of the wireless signal-emitting device; and calculate signal degradation data for the signal of interest based on information associated with the signal of interest in a static database including noise figure parameters of a wireless signal-emitting device outputting the signal of interest. The signal profile of the signal of interest, profile comparison result, and signal degradation data are stored in the apparatus.

Abstract: This disclosure introduces a mapping for creating good Doppler detection capable radar codes. The mapping transfers an existing digital radar code to the warped frequency domain by expressing the code elements as magnitudes and phases of selected frequencies. These frequencies are equispaced in the warped frequency domain to preserve the code's sidelobes after mapping. The frequency warping function may convert the multiplicative Doppler shift into an additive shift of the code pattern in the warped frequency domain, which allows Doppler shift detection.

Abstract: An ad hoc approach denoted as devoid clutter capture and filling (DeCCaF) that addresses the nonstationarity effects that arise when input radar waveform returns exhibiting dynamic spectra variations are processed to combat dynamic RFI is disclosed. Portions of the spectra of each input waveform return of a set of input radar waveform returns processed during the CPI may be filled with clutter information borrowed from other waveform returns of the set of waveform returns. DeCCaF may combined with an appropriate filter (e.g., a matched filter, a mismatched filter) to achieve results that are nearly indistinguishable from input radar waveform returns in which no spectral variation are present.

Abstract: A system for compensating for phase noise, with particular application in lidar, includes a compensation interferometer that receives a signal from a source, and splits it into a first and second path, with a path length difference ?? between them. Typically the path length is significantly less than that of the return distance to a target. The output of the compensation interferometer, which consists of phase noise generated in time ?? is vectorially summed during a time similar to a signal flight time to a target, and the result used to reduce phase noise present on measurements of a target. It further includes means for selecting ?? such that competing noise elements are reduced or optimised.

Abstract: A method for interference reduction in a stationary radar unit of a frequency-modulated continuous-wave (FMCW) type is provided. A sequence of beat signals is received, and a reference beat signal is calculated as an average or a median of one or more of the beat signals in the sequence. By comparing a difference between a beat signal and the reference beat signal, or a derivative of the difference, to one or more thresholds, a segment which is subject to interference is identified. The segment of the beat signal is replaced by one or more of a corresponding segment of an adjacent beat signal in the sequence, and a corresponding segment of the reference beat signal.

Abstract: A light detection and ranging (LIDAR) system encodes a frequency modulation (FM) modulated signal with a time of flight (TOF) signal as a power and frequency modulated signal. The system can emit the power and frequency modulated signal and apply processing to a signal reflection to generate a target point set. The target point set processing can include frequency processing to generate target points based on range and Doppler information, and TOF processing to provide TOF range information. The processing can include an FM processing path to extract FM signal information, and an AM processing path to extract the TOF signal information.

Abstract: A digital radio receiver has a matched filter bank of filter modules for receiving phase- or frequency-modulated radio signals. Each module cross-correlates a sampled signal with a respective multi-symbol filter sequence, using a plurality of samples in each symbol period. The matched filter bank calculates first values (zn(1)), for respective symbol periods, of a cross-correlation of the sampled signal with a first complex exponential function defined at sample points over one symbol period, and calculates second values (zn(?1)), for the respective symbol periods, of a cross-correlation of the sampled signal with a second, different, complex exponential function.

Abstract: A radar system includes a transmit section to emit a transmit signal. A chip-based front-end portion of the transmit section increases a frequency of an input signal to produce an intermediate signal and amplifies signal strength of the intermediate signal to produce the transmit signal. The frequency of the input signal is in a range of 76 gigahertz (GHz) to 80 GHz. The radar system also includes a receive section to receive a reflected signal resulting from reflection of the transmit signal by an object.

Abstract: Transmission antennas (2-#1 to 2-#M) transmit radiowaves of frequency bands uncorrelated with each other. Receivers (5-#1 to 5-#L) receives target-reflected waves reflected by a target. Pulse compressors (7-#1 to 7-#L) and transmission DBF units (8-#1 to 8-#L) suppress false peaks generated by the Doppler frequency in the target-reflected waves and combines the target-reflected waves. A reception DBF unit (9) and a target detector (10) detect the target based on the results of the combined signals.

Abstract: A radar system for a vehicle includes an antenna element installable at an outer shell of the vehicle, a dielectric waveguide, and a radar circuit configured to communicate with the antenna element via the dielectric waveguide. A vehicle includes a plurality of radar radio heads arranged at an outer shell of the vehicle, a plurality of waveguides, and a radar circuit configured to generate a common local oscillator signal and simultaneously provide respective radio frequency signal derived from the common local oscillator signal to the plurality of radar radio heads via the plurality of waveguides.

Abstract: A method, system and computer program product for tracking movement of an object, such as a hand. Speakers of a device to be controlled transmit frequency modulated continuous wave (FMCW) audio signals. These signals are reflected by the object and received by the microphones at the controlled device. The received and transmitted audio signals are mixed. A fast Fourier transform (FFT) is then performed on the mixed audio signals. One or more peak frequencies in the frequency domain of the FFT mixed audio signals are selected and used to estimate the distance between the object and the speakers of the controlled device. Furthermore, the velocity of the object is estimated. The coordinates of the object are then computed using the estimated distance between the object and the speakers and microphones of the controlled device and the estimated velocity of the object.

Abstract: A blind source separation (BSS) system comprises means for gathering wideband signal power spectral information without using special Fourier transform hardware/software systems and without using extremely large signal memories. The method involves taking the combined energy output of a large set of BSS filters that are operating under a blind source separation algorithm that looks for signals of interest, along with instantaneous filter characteristics such as center frequency, bandwidth and spectral response, and records a weighted spread energy into a frequency- and time-based histogram. This information can then be used to compare against the BSS signal output and signal energy which does not correspond to existing signal output is added to additional BSS signal output. This system can operate in real time, but uses long-term averaging to enhance signal detection.

Abstract: 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 th

Abstract: Provided is an apparatus for measuring a level of molten metal which has a simple structure and is highly robust against a change in level at a local portion of the surface of molten metal. The apparatus for measuring a level of molten metal according to a first aspect of the present invention is an apparatus which measures a level of molten metal in a mold. The apparatus includes an omnidirectional transmitting antenna; an omnidirectional receiving antenna; and a signal processor. The apparatus measures the level of molten metal in the mold using electromagnetic wave in ultra-high frequency range emitted into the mold by the omnidirectional transmitting antenna.

Abstract: A demultiplexing device that includes frequency-conversion and reception low-pass-filter units that perform a frequency converting process and a low-pass filtering process for causing a signal to pass through a desired band, perform downsampling to reduce a sampling rate to half of a data rate of an input signal, and output the signal, reception channel-filter units that waveform-shape a signal with a desired frequency characteristic and output the waveform-shaped signal. The demultiplexing device also includes a filter-bank control unit that generates a clock control signal for supplying a clock to frequency-conversion and reception low-pass-filter units and reception channel-filter units corresponding to signal passage bands, based on channel information, and a reception-clock supply unit that supplies a clock to frequency-conversion and reception low-pass-filter units and reception channel-filter units corresponding to signal passage bands, based on the clock control signal.

Abstract: A network analyzer includes an n-port network with two ports for measuring wave parameters of a measurement object. Each port has a feed for a radio-frequency signal from a signal source. Signal components of the radio-frequency signal fed into the respective port are reflected at the measurement object and the signal components of one or more radio-frequency signals fed into at least one other port are transmitted through the measurement object to the respective port are measured as wave parameters. The two ports are supplied with different radio-frequency signals, wherein frequencies or frequency bands are offset with respect to one another by a frequency offset. Reflected and transmitted signal components of the radio-frequency signals are measured at the same time at the two ports.

Abstract: The radar apparatus includes a target candidate detecting means for detecting a peak frequency at which the intensity of the power spectrum of a beat signal peaks as a target candidate, a road shape recognizing means to sequentially connect, along a predetermined direction, the target candidates detected to be stationary and present within a reference distance from one of the target candidates set as a reference target candidate for one or more measurement cycles and recognize an area formed by the sequentially connected target candidates as an edge of the road, a cruise environment estimating means to determine whether the cruise environment is a closed space or an open space based on the power spectrum, and a reference distance correcting means to shorten the reference distance when the cruise environment is determined to be a closed space.

Abstract: A radar system achieves unambiguous target range at a given PRI, in conjunction with unambiguous Doppler, by transmitting CW-LFM pulses and then separating the return signal into subpulses, without requiring any modifications to the transmit waveform. The CW-LFM pulses may be contiguous. The return signals are bandpass-filtered to generate the subpulses, and downconverted to a common frequency such as baseband. Each downconverted subpulse is matched-filtered to the FM slope, and the resulting matched-filtered subpulses are time-aligned. The time-aligned subpulses are Doppler-filtered to determine target velocity.

Abstract: One or more carrier signals in a multiple-carrier UE transmitter are frequency-adjusted to account for an estimated error in the separation frequency between the transmitted carrier signals. The adjustment is applied when generating the UL signals for the respective carrier frequencies in digital baseband of the UE. In one embodiment, one or more of the modulators that apply the carrier separation frequency additionally apply a frequency correction. In another embodiment, first mixers apply the carrier separation frequency to each different carrier signal. One or more carrier signal paths include a second mixer applying a frequency correction to the carrier signal. The RF modulation frequency may also be adjusted to partially compensate for the estimated carrier separation frequency error.

Abstract: A signal processing apparatus for a radar transceiver, which receives a reflected signal generated by a target object in response to a frequency modulated transmission signal, and generates a beat signal having a frequency difference between the transmission signal and a reception signal, includes: an azimuth angle detection unit that detects an azimuth angle of the target object on the basis of a peak signal in a frequency spectrum of the beat signal; a peak signal extraction unit that prioritizes extraction of a peak signal corresponding to a predetermined azimuth angle range and a predetermined relative distance range of the target object; and a target object detection unit that detects the target object from the extracted peak signal.

Abstract: A radar device is mounted on a vehicle, for detecting an object, and includes: a transmitting unit for transmitting an electromagnetic wave as a transmitter signal; a receiving unit for receiving a reflected signal that is reflected from the object as a receiver signal; a signal processing unit for measuring a distance and a relative velocity between the vehicle and the object on the basis of a beat signal that is obtained by the transmitter signal and the receiver signal; and an interference detecting unit for detecting the interference signal from another radar device or a communication device on the basis of a signal intensity of the frequency range that is not used for measuring the distance to the object and the relative velocity of the object.

Abstract: A radar apparatus measures an azimuth angle with a calculation device that performs super-resolution angle measuring processing in which relative speeds and relative distances among target objects are calculated, when two azimuth angles are obtained for a given target object that has been detected, the calculation device performs an other-signal detection processing in which, among other detected target objects, a target object is searched whose azimuth angle is the same as one of the two azimuth angles and whose beat frequency upon frequency-increasing modification or frequency-decreasing modification is the same as that of the given target object; and when, through the other-signal detection processing, another target object that satisfies the condition is detected, the calculation device eliminates one of two azimuth angles of the detected given target object, which is equal to the azimuth angle of said another target object detected through the other-signal detection processing.

Abstract: A scanning radar system suitable for detecting and monitoring ground-based targets includes a frequency generator, a frequency scanning antenna, and a receiver arranged to process signals received from a target so as to identify a Doppler frequency associated with the target. The frequency generator generates sets of signals, each set having a different characteristic frequency, and includes a digital synthesiser arranged to modulate a continuous wave signal of a given characteristic frequency by a sequence of modulation patterns to generate one set of signals. The frequency scanning antenna cooperates with the frequency generator to transceive radiation over a region having an angular extent dependent on the generated frequencies.

Abstract: The present invention is a method of finding range and velocity of a target in a radar system using a time scale factor. Specifically, sending at least one signal from at least one transmitter to a target. A return signal is then received from the target at each transmitter and the elapsed time is recorded. The range to the target and velocity of the target are calculated based on a time scale factor of the recorded elapsed times. These values are appropriately output to the user.

Abstract: A radar system comprising at least two spatially separated antenna units, each comprising one antenna. Each antenna unit comprising a signal generator connected to an antenna constitutes a transmitting antenna unit, and each antenna comprising a receiver connected to an antenna constitutes a receiving antenna. At least one receiving antenna unit is arranged for receiving at least one reflected signal, comprising signals transmitted from at least one transmitting antenna unit, having been reflected from at least one object, where the number of antenna units exceeds two. A processing unit is arranged to perform a correlation calculation, comparing at least one received signal with a set of mathematically manipulated copies. From said set, there is only one match for each reflected signal. The present invention also relates to corresponding methods.

Abstract: Embodiments of the invention are concerned with a radar system, and relates specifically to scanning radar systems that are suitable for detecting and monitoring ground-based targets.

Abstract: Disclosed is a DBF radar apparatus comprising: an antenna for radiating a transmit signal; a plurality of antennas for receiving the transmit signal reflected from an object; a first selector switch section for sequentially selecting output terminals of the plurality of antennas one at a time for connection to an input terminal by performing switching with a first period; a first downconverting section for downconverting, by using a portion of the transmit signal, a received signal input from each antenna; a low-frequency cut-off filter connected to an output of the first downconverting section; a second selector switch section for connecting an output of the low-frequency cut-off filter to a sequentially selected one of a plurality of A/D converters; and a digital signal processing section for receiving outputs of the plurality of A/D converters, and for applying prescribed processing to the outputs to detect the distance to the object or the relative velocity with respect to the object, wherein, when each a

Abstract: A sampled beat signal is cut out into two or more short time data in a time direction concerning each antenna component. From a frequency spectrum of the short time data, an interference element frequency of an interference wave is detected. From the interference element frequency of the interference wave, two or more candidates of the frequency before aliasing of the interference wave are produced, and phase correction is executed on each candidate. Digital Beamforming is executed on the corrected frequency so as to extract maximum peaks of the power of an azimuth direction, and the frequency candidate showing the maximum peak power is selected and the arrival azimuth of the interference element is estimated. A filter for suppressing the interference element is applied on the short time data from the estimated arrival azimuth of the interference element so as to suppress the interference element.

Abstract: A radar system comprises: a plurality of reception antennas; a transmission wave generating device; a transmission antenna; a mixer; an A/D converter; a storage device which stores the digitized beat signals in association with each of the reception antennas; a Fourier transformation device which Fourier transforms the stored beat signals; a digital beam forming device which generates beam signals at predetermined pitch angles based on the Fourier transformed signals; an orientation detecting device which detects an orientation of the object using the generated beam signals; a distance detecting device which detects a distance to the object using the generated beam signals; and a signal separation processing device which performs separation processing of the beat signals based on the detected orientation and distance of the object, using the beat signals associated with each of the reception antennas, which are Fourier transformed by the Fourier transformation device.

Abstract: An FM-CW radar includes a transmitting section, a mixing section, an A/D conversion section, a storage unit, and a signal processing section. The transmitting section transmits a continuous wave frequency-modulated with a triangular wave. The mixing section mixes the continuous wave transmitted and a reflected wave from a target, to generate a beat wave. The A/D conversion section A/D converts the beat wave into digital data. The storage unit includes a first storage section and a second storage section. The signal processing section reads data from the first storage section to process the read data. The A/D conversion section writes the digital data into the second storage section. The control section switches the first storage section and the second storage section alternately in synchronous with switching between up and down of the triangular wave.

Abstract: An FMCW radar device executes a frequency analysis for a beat signal in a frequency increase interval and a frequency decrease interval, to obtain frequency components in a predetermined high frequency range exceeding a frequency range corresponding to a target detection frequency range within which a target object for detection should be detected. Then the FMCW radar device calculates a value related to a sum of intensities of frequency components within the high frequency range respectively for each of the frequency increase interval and the frequency decrease interval. In the case that one of the calculated integrals is larger than a threshold, the FMCW radar device determines that the FMCW radar device is interfered with by a nearby radar device.

Abstract: A radar system in which a beat signal is generated by transmitting a transmission signal that is subjected to frequency modulation into a triangular wave and receiving a reflection signal from a target, the beat signal is sampled, and a window function is applied to yield a discrete frequency spectrum. When the window function is applied, a first window function having an amplitude that is gently attenuated from the center of the sampling period toward both sides thereof is applied in a lower frequency band in the frequency spectrum (at close range), and a second window function having an amplitude that is sharply attenuated from the center of the sampling period toward both sides thereof is applied in a higher frequency band in the frequency spectrum (at far range).

Abstract: A measuring apparatus for measuring a distance from an object to be measured has, a transmitting means for alternately modulating amplitudes of a first continuous wave having a first frequency and a second continuous wave having a second frequency for transmitting a transmission signal as a carrier wave using an AM signal. The AM signal is produced by an AM producing circuit for modulating the amplitudes. The transmission signal is reflected as a reflection signal by the object to be measured and received by a receiving circuit. A first distance calculating circuit calculates the distance using a phase difference between the first and second continuous waves. A second distance calculating circuit is used for demodulating the receipt signal, detecting a phase difference, and calculating a distance from the object to be measured using the detected phase difference. A determining circuit determines a final distance measurement based on the above calculations.

Abstract: Disclosed is a real-time pulse sorting apparatus of a preprocessor in a pulsed radiation detection system. The apparatus, responsive to digital signals generated by a system receiver, uses the instantaneous frequency as the address input to store discrete data groups in main memory. Each data group, comprising the digital data corresponding to a single analog-to-digital converter sample point, includes the RF signal amplitude, inter-channel phase difference, instantaneous frequency as well as a unique pulse number generated by the pulse sorting apparatus. The present invention further includes a TOA memory for storing the time-of-arrival of each pulse at an address given by the pulse number. The main memory, organized in the form of a frequency-based histogram, together with the TOA memory, linked to the main memory by means of the pulse number pointer, sorts and records RF signal data with minimal processor control and intervention.

Abstract: In a radio wave radar system using a two-frequency CW modulation method, it is possible to detect a distance between a host vehicle and a forward vehicle and to realize a stable ACC following travel, even in a condition in which the relative speed is 0. By combining the two-frequency CW modulation method with the frequency pulse CW modulation method, that is, by using combination with the two-frequency CW method when the relative speed occurs and the frequency pulse CW method when the relative speed is close to 0, even if the relative speed is 0, the IF signal obtained from the reflected wave from the forward vehicle can be generated to detect the existence of the ACC target vehicle, so that it is possible to realize a stable ACC following travel.

Abstract: A microwave sensor transmits a plurality of microwaves having different frequencies to a detection area and performs an object detecting operation based on reflected waves of the microwaves of an object present in the detection area. The microwave sensor includes object determining means that determines whether or not the object present in the detection area is an object to be detected, based on a moving direction of the object in the detection area.

Abstract: Disclosed is a radar apparatus equipped with a function for detecting an FM-AM conversion noise peak. When the direction of radiation is swept, any peak whose level remains substantially unchanged is judged to be a peak due to FM-AM conversion noise. Further, when FM modulation is stopped, any peak appearing in a region not lower than 50 kHz is judged to be a noise peak.

Abstract: The invention relates to remote distance measurement by means of a transmitted noise modulated probing signal (E), whereby at least one of a distance (Y(t)) and a velocity (V(t)) in relation to a signal transceiver (200) is determined. The probing of signal (E) is generated on basis of at least one first noise signal (x1(t), x2(t)). The transmitted signal (E) is presumed to be reflected to the signal transceiver (200) via at least one signal reflecting object in the form of an information carrying signal (e). This signal thus constitutes a delayed and possibly doppler shifted version of the transmitted signal (E). Moreover, according to the invention, a second noise signal (x2(t)) is added either to the probing signal (E) before it is transmitted or to the information carrying signal (e) before information pertaining to the reflecting object is derived there from.

Abstract: In an automotive radio wave radar, a center frequency of a transmitted wave is shifted at a certain cycle, and position information of an obstacle detected at three or more center frequencies is subjected to decision by majority to determine whether detection results of the obstacle are erroneous with the occurrence of jamming. If any of the detection results is determined to be abnormal, the abnormal result is discarded. An automotive radio wave radar is realized which can correctly perform the obstacle detection even in the event of jamming without causing erroneous obstacle detection or omission of the detection.

Abstract: A radar device includes a mixer that mixes an output of a transmit antenna 4 and an input of a receive antenna 6, an LPF 8, an A/D converter 9 that samples an output signal of the LPF 8 and subjects the sampled signal to A/D conversion, an FFT processing device 10 that subjects the converted signal to high-speed Fourier transformation, an aliasing discriminating/correcting device that discriminates a signal having a frequency component where aliasing occurs from a result by the FFT processing device 10 and corrects the signal to a signal of a normal frequency component where no aliasing occurs to obtain a distance and relative velocity data of the object, and a target object selecting device that selects necessary data from the distance and relative velocity data of the object which are obtained from the aliasing discriminating/correcting means.

Abstract: A wave-form generator drives a number of microwave generating devices each operating at different frequency bands. The output of each microwave generator is connected to its own transmission channel of limited bandwidth which contains all the non-linear components necessary for transmission such as an amplifier, T/R switch, rotary joint and beam switch. These individual channels are finally combined onto a common wideband channel which contains only substantially linear components such as a single waveguide and the antenna itself. Because of the isolation between channels there is little or no opportunity for the generation of harmonics or intermodulation distortions which would otherwise occur in a transmitter capable of operating over a very wide bandwidth.

Abstract: A radar is provided which transmits a radar wave whose frequency is so modulated as to rise, fall, and be kept constant cyclically. The radar uses beat signals produced by the radar wave and radar echoes received by two antennas to produce radar data on a target. When it is impossible to pair frequency peaks of the beat signals in a modulated frequency-rising and -falling ranges, the radar determines that the frequency peaks have arisen from different objects so that they overlap each other and uses frequency peaks of the beat signals in a constant modulated frequency range to acquire the radar data.

Abstract: In an object-detecting system using an FM-CW wave, points f1 to f4 corresponding to detection peaks of a reflected wave from a road-side object such as guardrail and points m1 and m2 corresponding to detection peaks of a reflected wave from a moving object such as a reflector of a preceding vehicle are indicated on two-dimensional coordinates along with the shape of a road ahead of a subject vehicle. Among the points f1 to f4, m1 and m2, the points f1 to f4 are determined as being provided by the reflected wave from the road-side object, and a distance from the subject vehicle to the object and a speed of the subject vehicle relative the object are calculated using the remaining points m1 and m2 excluding the points f1 to f4. Thus, only the moving object except the road-side object can be detected.

Abstract: A radar is provided which transmits a radar wave whose frequency is so modulated as to rise, fall, and be kept constant cyclically. The radar uses beat signals produced by the radar wave and radar echoes received by two antennas to produce radar data on a target. When it is impossible to pair frequency peaks of the beat signals in a modulated frequency-rising and -falling ranges, the radar determines that the frequency peaks have arisen from different objects so that they overlap each other and uses frequency peaks of the beat signals in a constant modulated frequency range to acquire the radar data.

Abstract: In an object-detecting system using an FM-CW wave, points f1 to f4 corresponding to detection peaks of a reflected wave from a road-side object such as guardrail and points m1 and m2 corresponding to detection peaks of a reflected wave from a moving object such as a reflector of a preceding vehicle are indicated on two-dimensional coordinates along with the shape of a road ahead of a subject vehicle. Among the points f1 to f4, m1 and m2, the points f1 to f4 are determined as being provided by the reflected wave from the road-side object, and a distance from the subject vehicle to the object and a speed of the subject vehicle relative the object are calculated using the remaining points m1 and m2 excluding the points f1 to f4. Thus, only the moving object except the road-side object can be detected.

Abstract: The intrusion detection system comprises a pair of narrow-beam microwave detectors exploiting Doppler effect and independently operating. A processing unit analyses the signals received by both detectors versus time and Doppler frequencies and amplitude. Analysis of such data allows detecting an actual intrusion. The processing unit also analyses the steady presence of the radio-frequency signal at each detector, to ascertain possible failures or tampering of the system.

Abstract: In a radar, a coupler extracts a part of a transmission signal as a local signal and a mixer mixes a reception signal from a circulator and the local signal so as to output an intermediate frequency signal which is the frequency difference between the transmission signal and the reception signal. An IF-amplifying circuit amplifies the intermediate frequency signal and an AD converter converts the signal to digital data. A DC-removing unit removes a DC component by subtracting the average from the data and an FFT operation unit performs fast Fourier transform so that the distance to a target and the relative velocity of the target are calculated based on a peak included in the frequency spectrum.

Abstract: The crossover detection method of a radar apparatus according to the present invention calculates distance/relative velocity information at a multitude of different clock times, using a beat signal; calculates predicted distance/relative velocity information indicating distance/relative velocity, respectively, of a target after a prescribed time has elapsed; calculates predicted distance/relative velocity errors by subtracting the calculated distance/relative velocity information from the calculated predicted distance/relative velocity information, respectively; calculates degree of similarity information, based on the predetermined average predicted distance/relative velocity errors and the calculated predicted distance/relative velocity errors; and determines whether there is crossover, based on the above information.

Abstract: An FM-CW radar apparatus capable of detecting a stationary object, in particular, an overbridge, located above the road ahead in a simple manner uses a traveling wave antenna as a transmitting antenna, and includes a means for varying, in upward and downward directions the projection angle of a combined beam pattern of a transmitted wave radiated from the traveling wave antenna, and an overbridge is detected by varying the projection angle of the combined beam pattern in the upward direction using the varying means. Further, a phase shifter for varying the projection angle of the beam pattern in upward/downward directions by controlling the phase of the radio wave to be transmitted or received is provided on either a transmitting antenna or a receiving antenna or on a transmitting/receiving antenna, and an overbridge is detected by controlling the phase shifter and varying the projection angle of the beam pattern in the upward direction.