Abstract: A transmitter system can have a higher power transmitter and a lower power that are configured to transmit a pair of unbalanced radio frequency beams to a target so as to produce a difference frequency in the target. The difference frequency can disrupt operation of a device, such as a weapon. The difference frequency can provide a radar return. The use of a higher power transmitter and a lower power transmitter reduces costs, size, and weight as compared to the use of two higher power transmitters.

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: The present invention relates to a procedure for measuring distance. It applies notably in respect of short-range radars, but not exclusively. The method uses an electromagnetic wave comprising at least one emission sequence (31, 32, 33, 34, 35) of the FSK type, at least two emission frequencies (F1, F2), emitted successively towards the said target a given number p of times inside the sequence. The gap ?F between the emission frequencies (F1, F2) is substantially equal to an integer number k of times the repetition frequency (SPRF) of the cycle of frequencies, the distance measurement being obtained on the basis of the measurement of difference of phases ?? between the signals received corresponding respectively to a first frequency (F1) and to a second frequency (F2).

Abstract: There are provided a distance measuring device and a distance measuring method characterized by “simple configuration”, “capability of measuring a near distance”, and “a small measurement error” like a distance measuring device using a standing wave. The distance measuring device includes a signal source (1) for outputting a signal having a plurality of different frequency components within a particular bandwidth, a transmission unit (2) for transmitting a signal as an undulation, s mixed wave detection unit (3) for detecting a mixed wave VC obtained by mixing a progressive wave VT transmitted and a reflected wave VRk of the progressive wave VT reflected by a measurement object (6), a frequency component analysis unit (4) for analyzing the frequency component of the mixed wave VC detected, and a distance calculation unit (5) for obtaining a distance spectrum by subjecting the analyzed data further to spectrum analysis, thereby calculating the distance to the measurement object (6).

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 wireless sensor device includes a transmission signal generation unit that generates a frequency-spread high frequency transmission signal such that a transmission frequency is continuously increased and decreased with a predetermined period, a transmitter antenna that radiates the high frequency transmission signal, a receiver antenna that receives a reflected wave from an object having received the high frequency transmission signal, and outputs a frequency-spread high frequency reception signal, a mixer circuit that receives a part of the high frequency transmission signal as a first frequency-spread high frequency signal, receives the high frequency reception signal as a second frequency-spread high frequency signal, and outputs a DC beat signal by operating as a phase detector when frequencies of the first and second signals coincide with each other, and a DC component extraction circuit that extracts the DC beat signal from an output signal of the mixer circuit.

Abstract: A broadband radar arrangement having a radar transmitter and a radar receiver mounted above a targeted water surface to monitor and determine a sea state of the targeted water surface. Spectrally spaced signals are transmitted by the transmitter and received by the receiver, via a direct path and via a forward scattered path off the targeted water surface. An interference pattern of interfering direct path signals and forward scattered signals is used to determine an instantaneous height of the water surface and also to determine the sea state of the targeted water surface.

Abstract: A radar apparatus and method for determining the range to and velocity of at least one object comprising, transmitting a plurality of RF signals, each comprising a particular frequency and being transmitted during a particular unique finite period, the plurality of signals collectively comprising at least one first subset of signals having the same frequency and at least one second subset of signals having different frequencies, receiving the plurality of signals after reflection from an object, determining a phase difference between each of the signals and the corresponding reflected signal, each piece of phase difference information herein termed a sample, organizing the samples in two-dimensions wherein, in a first dimension, all samples have the same frequency and, in a second dimension, all consecutive samples are separated from each other by a fixed time interval; processing the samples in the first dimension to determine a phase rotation frequency corresponding to the samples in the first dimension, th

Abstract: A radar wherein, in response to an increase in the level of noise appearing in a frequency spectrum caused by interference being superimposed on a beat signal, peaks exceeding a threshold are extracted as target peaks in an ordinary state and a predetermined number of peaks in descending order starting from the peak having the highest peak value are extracted in the case where interference occurs.

Abstract: Various aspects of the present invention are shown and described, each of which has stand alone utility in a navigated medical environment. A receiver position calibration system and method facilitates calibration of a reference frame prior to each navigated procedure. A concept and application of confidence weights is introduced. Confidence weights can be applied to distance calculations to mitigate the effects of interference and increase the tolerance of the navigated medical system. Multi-path interference is minimized through the transmission of a signal having a pattern of unique frequencies and filtering of the distance calculations for each frequency to identify the ‘best’ distance in the presence of multi-path interference. A position determination method and system that transmits a signal having multiple frequency components permits positions to be identified with high resolution over a large area.

Abstract: A target signal analyzer having at least one receiving antenna configured to receive the target signal, and a parallel array of oscillator rings. Each oscillator ring is operatively coupled to receive the target signal from the receiving antenna. Each oscillator ring has an odd number of at least three bistable, nonlinear oscillators circularly coupled to each other such that only one-way signal flow is allowed between the oscillators in each oscillator ring. Each of the oscillator rings is configured to oscillate and thereby produce a response signal only when the target signal frequency is within a designated frequency band. For every designated frequency band in a spectrum of interest, at least one of the oscillator rings is configured to produce a response signal.

Abstract: A method and device are provided for measuring distance and relative speed of a plurality of objects with the aid of an FMCW radar, transmitted signals being reflected by objects, and the reflected signals being received and mixed with the transmitted signals. A combination of distance and relative speed values is assigned to the mixer output frequencies of each frequency ramp for each object, and the distance and relative speed of a possible object are determined from points of intersection of a plurality of distance and relative speed combinations. The apparent (unreal) objects are eliminated by modifying the frequency slope of at least one frequency ramp according to the random principle in a subsequent measurement cycle.

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 obstacle detection system comprises a transmission antenna operable to radiate a radio frequency (RF) signal and a transmitter operable to control transmission of the RF signal from the antenna. The obstacle detection system also comprises a receiver antenna operable to receive a reflection of the RF signal; and processing circuitry operable to analyze a plurality of characteristics of a radar cross section (RCS) of the received reflection to identify an obstacle and one or more physical attributes of the obstacle.

Abstract: There is provided a radar system for detection of one or more objects. The radar system comprises a radar wave transmitter for simultaneously transmitting a CW radar signal and a FM-CW or MF radar signal, and a first radar wave receiver for receiving CW and FM-CW or MF radar signals, reflected from one or more objects present in a detection range of the radar system. The system may further comprise a first CW mixer for mixing CW transmission signals and reflected CW signals received by the first receiver, and a first FM-CW or MF mixer for mixing FM-CW or MF transmission signals and corresponding reflected FM-CW or MF signals received by the first receiver.

Abstract: A coal-mining machine uses a ground-penetrating radar based on a software-definable transmitter for launching pairs of widely separated and coherent continuous waves. Each pair is separated by a constant or variable different amount double-sideband suppressed carrier modulation such as 10 MHz, 20 MHz, and 30 MHz. Processing suppresses the larger first interface reflection and emphasizes the smaller second, third, etc. reflections. Processing determines the electrical parameter of the natural medium adjacent to the antenna. Deep reflections at 90-degrees and 270-degrees create maximum reflection and will be illuminated with modulation signal peaks. Quadrature detection, mixing, and down-conversion result in 0-degree and 180-degree reflections effectively dropping out in demodulation.

Abstract: A ground-penetrating radar comprises a software-definable transmitter for launching pairs of widely separated and coherent continuous waves. Each pair is separated by a constant or variable different amount double-sideband suppressed carrier modulation such as 10 MHz, 20 MHz, and 30 MHz Processing suppresses the larger first interface reflection and emphasizes the smaller second, third, etc. reflections. Processing determines the electrical parameter of the natural medium adjacent to the antenna. The modulation process may be the variable or constant frequency difference between pairs of frequencies. If a variable frequency is used in modulation, pairs of tunable resonant microstrip patch antennas (resonant microstrip patch antenna) can be used in the antenna design. If a constant frequency difference is used in the software-defined transceiver, a wide-bandwidth antenna design is used featuring a swept or stepped-frequency continuous-wave (SFCW) radar design.

Abstract: A system (200) and method (400) for determining the location of an object is provided. A plurality of radio transceivers (101,201,203,205) are disposed about a location of interest (221). One or more tags (102) are coupled to an object. The radio transceivers (101,201,203,205) transmit radio frequency signals (115,215,217,219) to the tag (102), which backscatters a return signal (116,216,218,220) having a unique identifier modulated therein due to a switch (108) switching between two or more loads (110,112) in accordance with a unique identification code (118). A location determination module (107) then determines the location of the tag (102) by using a course location estimate (502), a fine location estimate (503), or combinations thereof. A object modeling module (109) can create multidimensional models using the locations of the tags (102).

Abstract: A time needed until measurement values are obtained in a two-frequency continuous wave radar systems is reduced. An object detection system that emits transmission signals, as transmission waves, whose frequencies have been modulated successively into a plurality of stepped frequencies, and receives echoes of the transmission waves reflected from target objects, thereby calculating relative velocities of the target objects by frequency-analyzing reception signals obtained from the received echoes. The target object detection system includes: a frequency modulation component that repeatedly executes frequency-modulation processes to successively modulate the transmission signals into those of the stepped frequencies, within a minimum measurement time in which a desired velocity resolution is achieved; and a frequency-analysis component that frequency-analyzes throughout the repeated frequency-modulation processes the reception signals processed by the frequency-modulation component.

Abstract: The invention relates to a clock pulse control circuit for generating a transmit clock pulse (ts) and a sampling clock pulse (ta; tb; tc), wherein the clock pulse control circuit comprises a first oscillator for generating a first clock pulse (ts) of a first frequency, and a second oscillator for generating a plurality of second clock pulses (ta; tb; tc), that are shifted in time in relation to each other, of a second frequency. The clock pulse control circuit is designed such that based on the first clock pulse (ts) and the plurality of second clock pulses (ta; tb; tc) the transmit clock pulse (ts) is providable to a transmit pulse generator, and the sampling clock pulse (ta; tb; tc) is providable to a sampling pulse generator.

Abstract: A method for extension of unambiguous range and velocity of a weather radar. To avoid pulse overlaying, the pulse repetition time of a single pulse can be extended such that any return echo will arrive at the radar before the next pulse is transmitted. When pulse repetition time is increased, the maximum unambiguous range increases while the maximum unambiguous velocity decreases. The pulse overlaying can be avoided if consecutive pulses are sent on different frequencies that are far enough from each other to allow separation of pulses arriving simultaneously at the radar. When different frequencies are used an unknown phase difference is generated by distributed atmospheric targets to the return signals. This normally prevents use of the shorter pulse repetition time for velocity calculation.

Abstract: There are provided a distance measuring device and a distance measuring method characterized by “simple configuration”, “capability of measuring a near distance”, and “a small measurement error” like a distance measuring device using a standing wave. The distance measuring device includes a signal source (1) for outputting a signal having a plurality of different frequency components within a particular bandwidth, a transmission unit (2) for transmitting a signal as an undulation, s mixed wave detection unit (3) for detecting a mixed wave VC obtained by mixing a progressive wave VT transmitted and a reflected wave VRk of the progressive wave VT reflected by a measurement object (6), a frequency component analysis unit (4) for analyzing the frequency component of the mixed wave VC detected, and a distance calculation unit (5) for obtaining a distance spectrum by subjecting the analyzed data further to spectrum analysis, thereby calculating the distance to the measurement object (6).

Abstract: A system and method for controlling access to a wireless networking system using RFID tags is provided. The security system and method uses RFID tags to determine the location of mobile computing device. The security system and method selectively allows access to the wireless networking system based on the determined location of the mobile computing device. For example, the security system and method will permit access to the wireless networking system if the mobile computing device is determined to be in an area of permitted access. Conversely, the security system and method will deny access to the wireless networking system if the mobile computing device is determined to be not within an area of permitted access. Thus, the system and method is able to effectively control access to the wireless networking system by only permitting access to mobile devices within designated areas.

Abstract: A ground-penetrating radar comprises a transmitter for launching pairs of widely separated and coherent continuous waves. Each pair is separated by a different amount, such as 10 MHz, 20 MHz, and 30 MHz. These are equivalent to modulation that have a phase range that starts at 0-degrees at the transmitter antenna which is near the ground surface. Deep reflectors at 90-degrees and 270-degrees will be illuminated with modulation signal peaks. Quadrature detection, mixing, and down-conversion result in 0-degree and 180-degree reflections effectively dropping out in demodulation.

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: A radar device includes: an oscillator for generating a wave at a plurality of transmission frequencies; a transmitting antenna; a receiving antenna; a receiver for generating a real received signal; a Fourier transform unit for performing a Fourier transform on the real received signal in a time direction; a spectral peak detecting unit for receiving an input of a result of the Fourier transform to extract peak complex signal values of Doppler frequency points having a maximum amplitude; a distance calculating unit for storing the peak complex signal values and for calculating a distance to a reflecting object based on the stored peak complex signal values to output the obtained distance as a measured distance value; and a distance sign determining unit for determining validity of the measured distance value and for outputting the measured distance value and the Doppler frequency according to a result of determination.

Abstract: A distance measuring apparatus comprising a transmission antenna to radiate a transmission radio wave; a reception antenna to receive a reflected signal from a target; an analog-to-digital converter to perform an analog-to-digital conversion for converting a reception signal; and a signal processing unit to process the converted signal and to detect the target, in which a transmission frequency of the transmission radio wave to be radiated is switched at a timing synchronized with a sampling frequency of the analog-to-digital conversion, the transmission frequency is switched in accordance with an arbitrary pattern within a frequency band, and the reception signal is rearranged in order on the basis of the arbitrary pattern at a time of the transmission to then be subject to a radar signal processing.

Abstract: The radar apparatus of the present invention can obtain distance to a target and speed with higher accuracy even when multiple targets are running within a detecting field of a radar. The radar apparatus can transmit a radio wave by alternately switching a section having a frequency slope and a section having no frequency slope with the radar for simultaneously transmitting a couple of frequencies having a frequency difference. Measurement of distance to the target and relative speed is conducted in the above two sections, results of measurement are compared with each other in the adjacent sections, and the result of measurement is determined correct only when there is no inconsistency in these measurement results.

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: Systems and methods for avoidance of partial pulse interference in radar. The systems and methods include a radar processor for generating control signals that direct the generation and transmission of two consecutive radar pulses using a waveform and pulse train generator and transmitter. The systems and methods also include receiving reflected echoes corresponding to the transmitted pulses using a receiver and processing the echoes using an analog to digital converter, filter, and digital signal processor to separate echoes from each pulse, process them, and combine the results to avoid partial pulse interference while maintaining pulse energy and an acceptable signal to noise ratio.

Abstract: A radar device includes: an oscillator for generating a wave at a plurality of transmission frequencies; a transmitting antenna; a receiving antenna; a receiver for generating a real received signal; a Fourier transform unit for performing a Fourier transform on the real received signal in a time direction; a spectral peak detecting unit for receiving an input of a result of the Fourier transform to extract peak complex signal values of Doppler frequency points having a maximum amplitude; a distance calculating unit for storing the peak complex signal values and for calculating a distance to a reflecting object based on the stored peak complex signal values to output the obtained distance as a measured distance value; and a distance sign determining unit for determining validity of the measured distance value and for outputting the measured distance value and the Doppler frequency according to a result of determination.

Abstract: A multi-tone CW radar (14) is used to project signals from an antenna (22) and to receive returns with the same antenna. The phase differences between the outgoing signals and the returns are analyzed to determine the existence of motion and the range to a moving object (10). A model is made which has range as its major parameter. A waveform associated with the phase difference between outgoing signals and returns for one of the tones is compared to templates produced by the model to determine which has a range that most closely matches. By varying the range parameters, when a match is detected the range to the object can be obtained even if its motion is pseudorandom. If the range is measured with multiple units it is possible to measure the location of the object. This can be done assuming a grid and algorithmically combining the ranges from the units.

Abstract: An antenna array is provided for an RFID reader, which includes a first reader antenna tuned to operate at a first frequency and a second reader antenna tuned to operate at a second frequency different from the first frequency. The first and second antennas are preferably arranged in an overlapping arrangement or an opposing magnetic flux arrangement to reduce the effect of antenna self resonance.

Abstract: The present invention is a combined aircraft TCAS/Transponder with common antenna system and transmitter. Common TCAS/Transponder multi-monopole top and bottom antennas may be connected to a top and bottom antenna modules, the top and bottom antenna modules being electrically coupled to the combined TCAS/Transponder transmitter/receiver block through connection lines.

Abstract: Sensing characteristics of an object includes transmitting a stepped-frequency radar through an object and detecting, with multiple receiving structures, deflected portions of the radar signal. The detected portions are processed to generate processed data including information associated with amplitudes and phases of the deflected portions, and with the locations of the receiving structures at which the deflected portions were detected. The processed data is analyzed to determine information corresponding to dielectric properties particular positions within the object.

Abstract: A sensor system on motor vehicles for locating objects in front of the vehicle, wherein at least two sensors, each having a locating depth of at least 50 m, are arranged in such a way on both sides of longitudinal center axis of the vehicle that their locating angular ranges together cover the entire vehicle width as of a first distance d1, and overlap each other as of a second distance d2.

Abstract: A method for determining the distance between a base station (SLG) and a mobile object (DT1–DT3). A HF carrier frequency and an offset frequency (df) are predetermined for a QAM modulation. The HF carrier frequency is increased and decreased by the offset frequency in sequence over time in such a way that the HF carrier base frequencies (fo+df, fo?df) resulting in an HF carrier signal (TS) thus modulated exhibit an identical phase when the frequency is changed. The HF carrier signal is subsequently transmitted and simultaneously mixed (MIX) with an HF carrier signal (RS) that has been backscattered by the mobile object to obtain a carrier phase signal (PS). The corresponding carrier phase (PH1, PH2) for the two HF carrier base frequencies is determined in sequence over time. The difference (dPH) between these phases is used to calculate the distance between the base station and the respective mobile object.

Abstract: An improved system is provided for aiming a shotgun-based or other countermeasure system so as to be able to countermeasure incoming rockets or projectiles. In one embodiment a shotgun aimed and controlled by the subject system projects a pattern of pellets to intercept a rocket-propelled grenade or incoming projectile. The fire control system uses a CW two-tone monopulse radar to derive range and angle of arrival within 150 milliseconds, with range and angle of arrival measurements having approximately twice the accuracy of prior CW two-tone monopulse radars. The improvement derives from using all of the information in the returned radar beams and is the result of the recognition that one can use the Sum and Difference signals to assemble a two-by-two Rank One matrix that permits using singular value decomposition techniques to generate range and angle of arrival matrices in which all available information is used and in which noise is eliminated.

Abstract: A method and apparatus is provided for correcting the phase difference estimate derived from a two-tone CW radar to correct velocity-induced range estimate phase errors by offsetting the phase difference estimate with a phase correction equal to either of the Doppler frequencies associated with returns from an object multiplied by the time interval between the samplings of the returned waveforms. The correction effectively eliminates the velocity-induced slippage between the phases of the retuned waveforms so that a comparison between the phases of the waveforms can be made to reduce or substantially eliminate range estimate bias.

Abstract: A radar system having a beamless emission signature is described. In one implementation, the radar system includes a transmission system and a receiver system. The transmission system is configured to transmit a pattern comprising a plurality of radar signals having different frequencies simultaneously. The receiver system is configured to receive a reflection of the pattern and combine the plurality of radar signals into a composite waveform forming an image of a target.

Abstract: A distance can be measured with high resolution. A frequency controller (7) controls a voltage control oscillator (2) so as to change a signal source frequency f in a range containing two center frequencies f1 and f2 and transmits it as a traveling wave from an antenna (4) to a target (5). A reflected wave reflected by the target (5) and the traveling wave interfere each other and form a standing wave. A power detector (6) detects power corresponding to the amplitude of the standing wave and performs Fourier transform based on the two center frequencies f1 and f2 in Fourier transform means (11, 12), respectively, thereby calculating radar image functions P1(x), P2(x). The distance d to the target (5) satisfies the conditions that the phase difference of the two radar image functions zero-crosses and the amplitude of the radar image functions becomes maximum. The zero cross point of the phase difference is a zero cross point of a linear function and can be identified with high resolution.

Abstract: A radar has a transmission section, a reception section that receives a reflected wave of the transmission wave, a transmission switch section, a delay section that delays a predetermined timing, a reception switching section, a difference processing section, and a calculation section. The transmission section switches between a first frequency and a second frequency to transmit a transmission wave having one of the frequencies. The transmission switch section switches between turning-on and turning-off of an operation of the transmission section at the predetermined timing. The reception switching section switches between turning-on and turning-off of an operation of the reception section according to the timing delayed. The difference processing section outputs a difference between the transmission wave and the reflected wave. The calculation section calculates a distance on a basis of a delay amount, when a detection waveform has a difference frequency between the first frequency and the second frequency.

Abstract: A system and method is provided for locating objects using RFID tags. The system and method uses an RFID reader and a distance calculator to efficiently and accurately determine the location of objects that include an RFID tag. The RFID reader transmits a plurality of signals to the RFID tag, with the plurality of signals having different fundamental frequencies. In response, the RFID tag backscatter modulates the plurality of transmitted signals to create a plurality of backscatter modulated signals. The RFID reader receives and demodulates the plurality of backscatter modulated signals. The distance calculator determines the phase of the plurality of backscatter modulated signals and determines a rate of change of the phase in the backscatter modulated signals with respect to the rate of change in the fundamental frequency of the transmitted signals and uses this information to calculate the distance to the RFID tag.

Abstract: Actual correlation data is stored at 38A. Such actual correlation data is data representation(s) of correlation(s) between or among distance(s) to object(s) intended to be detected and phase difference(s) of respective reflected wave(s) established with due consideration having been given to reflection of microwave(s) by object(s) (ceiling surface(s), wall surface(s), floor surface(s), etc.) other than object(s) intended to be detected which may be present within area(s) intended to be protected. Distance(s) to object(s) intended to be detected is or are measured, based on such actual correlation data, from phase difference(s) of respective reflected wave(s) that has or have been detected.

Abstract: A radar apparatus includes: a modulation signal generating circuit that generates a modulation signal; a carrier wave generating circuit that generates a carrier wave; a modulation circuit that outputs a high frequency signal generated by modulating the carrier wave using the modulation signal that has been inputted; a modulation signal extracting circuit that extracts the modulation signal from the high frequency signal that has been inputted; and a detection signal generating circuit that generates a detection signal, which can be used to measure a distance to a measured object, based on the modulation signal extracted by the modulation signal extracting circuit from a component, out of the high frequency signal that has been transmitted via a transmission antenna, the component having been reflected by the measured object and received by a reception antenna.

Abstract: An arrangement comprising a master unit and one or more slave units, where the master sends out bursts, at specified intervals, in a frequency hopping manner, with each burst being at a different frequency. The slave responds with acknowledgements, and the signal strengths of the acknowledgments are used to select one or more of the acknowledgments as the signals used for distance, or range, estimation. Advantageously, the durations of the intervals are fairly long during normal operation, and short at times when certain conditions occur, such as loss of communication or when accurate range estimation is required. Also, the slave is adapted to sleep while it is not expecting a burst transmission from the master, thereby saving power. The frequency hopping sequencing is preferably pseudo random, with a different sequencing of the same set of frequencies at different modes of operation.

Abstract: A sensor has a trigger level that is set in advance in which a distance to a detected object and a signal level of waves reflected from the object are associated. The sensor only dispatches an object detection signal indicating that the detected object is an object to be considered as a detection target having a size larger than a predetermined size when a reflected wave that has a signal level exceeding the trigger level is received.

Abstract: In an FM-CW radar system, a frequency modulating wave output from said modulating signal generator has a frequency variation skew with respect to a time axis (modulation skew), and the radar system includes a means for varying the modulation skew by controlling the modulation frequency amplitude or modulation period of the modulating signal. The radar system further includes a means for discriminating a signal component varying in response to the variation of the modulation skew, thereby discriminating a signal related to a target object from other signals. In the case of an FM-CW radar system that performs transmission and/or reception by time division ON-OFF control, the radar system includes a means for discriminating a signal which, when the frequency used to perform the ON-OFF control is varied, varies in response to the variation of the frequency, thereby discriminating a signal related to a target object from other signals.

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 system is provided for generating multiple frequencies in a specified frequency band, with a specified step size between frequencies, in which the spectral purity of the frequencies is assured. The switching speed between frequencies is very fast, limited only by the speed of the switches used. In one embodiment, only five tones are generated as the base for the rest of the synthesis, in which the relationship of the five tones is f0+/??f0 and +/? 1/16f0. The subject system may be utilized in air defense systems for generating the transmit channels to be able to permit a missile seeker to transmit a signal at the appropriate frequency. In one embodiment, spectral purity is achieved by providing a number of stages of up converting, expanding, and dividing down of an input signal.