Abstract: The transmission antenna (10) of the high-resolution synthetic aperture side view radar system comprises a plurality of sub-apertures (7, 8, 9). In each individual transmission pulse, said sub-apertures are controlled in such a manner that a spatiotemporally non-separable multi-dimensional high-frequency waveform is produced as an transmission signal pulse form, such that the modulation of each transmission pulse has a spatiotemporal diversity which is not described by the product having functions which are independent from each other and which are dependent on, respectively, only one spatial dimension. The thus produced transmission pulse form is combined to a capture-sided spatial filtering by means of digital beamforming adapted to said transmission signal pulse form.

Abstract: According to one embodiment, an radar apparatus includes a signal processor, a transmitting unit, an antenna, a first receiving unit, and a second receiving unit. The signal processor generates first or second pulses, and generates a control signal having first or second states. The transmitting unit converts the first and second pulses into first and second transmission pulses. The antenna radiates the first and second transmission pulses and receives reflection pulses to generate a reception signal. The first receiving unit includes first and second receiving circuits which processes the reception signal to generate first and second processed signals, respectively, and outputs one of the first and second processed signals depending on the state of the control signal. The second receiving unit processes the one of the first and second processed signals.

Abstract: A radar or sonar system amplifies the signal received by an antenna of the radar system or a transducer of the sonar system is amplified and then subject to linear demodulation by a linear receiver. There may be an anti-aliasing filter and an analog-to-digital converter between the amplifier and the linear receiver. The system may also have a digital signal processor with a network stack running in the processor. That processor may also have a network interface media access controller, where the system operates at different ranges, the modulator may produce pulses of two pulse patterns differing in pulse duration and inter-pulse spacing, those pulse patterns are introduced and used to form two radar images with the two images being derived from data acquired in a duration not more than twenty times larger than the larger inter-pulse spacing, or for a radar system, larger than one half of the antenna resolution time. One or more look-up tables may be used to control the amplifier.

Abstract: The present invention is a method and apparatus that provides detection, characterization, and intuitive dissemination of targets. This disclosure combines improvements to ultra-wideband (UWB) sensing and machine target characterization with a means to convey data in a format that is quickly and readily understood by practitioners of the technology. The invention is well suited for Situational Awareness (SA) support in areas that are occluded by rain, fog, dust, darkness, distance, foliage, building walls, and any material that can be penetrated by ultra-wideband RF signals. Sense Through The Wall (STTW) performance parameters including target range, stand-off distance, and probability of detection are improved herein by combining a dynamically positioned sliding windowing function with orthogonal feature vectors that include but are not limited to time amplitude decay, spectral composition, and propagation time position in the return signal data.

Abstract: Provided is a receiving device that is used for a spread spectrum radar apparatus, receives a spectrum-spread signal, and obtains a precise radar spectrum, and includes: a despreading unit that (i) generates first and second despread signals that are generated by despreading a reception signal using a pseudo-noise code, the second despread signal passing through a transmission line carrying a current having a current value identical to a current value of a current carried by a transmission line through which the first despread signal passes, and (ii) includes a first transistor pair including first and second transistors having an identical characteristic, the first transistor outputting the first despread signal, and the second transistor outputting the second despread signal; and a quadrature demodulating unit that generates an in-phase signal and a quadrature signal by quadrature-demodulating the first despread signal and the second despread signal, respectively.

Abstract: A level measuring instrument has a variable transmitting power for measuring a filling level in a tank. The level measuring instrument includes a generator unit generating one of a first oscillator signal and a second oscillator signal. The generator unit generates a transmit signal from one of the first oscillator signal and the second oscillator signal. The level measuring instrument includes further a controller controlling the generator unit. The generator unit generates one of first and second transmitting powers for the transmit signal.

Abstract: In one embodiment, an ultra wide band (UWB) radar includes: a substrate; a plurality of antennas adjacent the substrate, the plurality of antennas being arranged into a plurality of sub-arrays; an RF feed network adjacent the substrate, the RF feed network coupling to a distributed plurality of amplifiers integrated with the substrate, wherein the RF feed network and the distributed plurality of amplifiers are configured to form a resonant network such that if a timing signal is injected into an input port of the RF feed network, the resonant network oscillates to provide a globally-synchronized RF signal across the network; a plurality of pulse-shaping circuits corresponding to the plurality of sub-arrays, each pulse-shaping circuit being configured to receive the globally-synchronized RF signal from the network and process the globally-synchronized RF signal into pulses for transmission through the corresponding sub-array of antennas; and an actuator for mechanically scanning the UWB radar so that the pulse

Abstract: A system supporting data retrieval from a plurality of wireless sensor nodes is defined. The system includes the plurality of wireless sensor nodes and a data retrieval device. The plurality of wireless sensor nodes include a transceiver receiving a first signal and transmitting a second signal. The second signal includes a sensed datum or an encoded statistic based on the sensed datum identified at the plurality of wireless sensor nodes. The data retrieval device includes a plurality of antennas transmitting the first signal toward the plurality of wireless sensor nodes and receiving the second signal from the plurality of wireless sensor nodes, and a processor coupled to receive the received second signal from the plurality of antennas, the processor defining a virtual receive signal from the received second signal for the plurality of antennas and processing the defined virtual receive signal to determine the identified sensed datum.

Abstract: A method for determining a refractivity profile of an atmosphere of the Earth. The method may involve: generating radar signals from a radar device located above the Earth's surface toward the Earth's surface; measuring a time of flight and a reflected intensity of reflected radar signals received back at the radar device; using the measured time of flight and the reflected intensity of the reflected radar signals received by the radar device to determine a distance to a radar horizon where the radar signals are tangent to the Earth's surface; and using the distance to the radar horizon to determine a refractivity profile of the atmosphere through which the radar signals and the reflected radar signals have travelled.

Abstract: A height-finding 3D avian radar comprises an azimuthally scanning radar system with means of varying the elevation pointing angle of the antenna. The elevation angle can be varied by employing either an antenna with multiple beams, or an elevation scanner, or two radars pointed at different elevations. Heights of birds are determined by analyzing the received echo returns from detected bird targets illuminated with the different elevation pointing angles.

Abstract: A method and system for SNR enhancement in pulse-Doppler coherent target detection for applications in the fields of radar and ultrasound. In accordance with the method of the invention, complex signals are obtained for each of two or more sub-intervals of the time-on-target interval, allowing simultaneous range and Doppler measurements. A coherent integration is the performed on the signals to generate complex-valued folded matrices. The folded matrices are unfolded and target detection is then performed in a process involving one or more of the unfolded matrices. A pulse-Doppler coherent system is also provided configured for target detection by the method of the invention.

Abstract: A method and apparatus for remotely sensing the content in a field of view are disclosed. The method includes transmitting a coherent optical signal into a field of view; receiving and detecting a reflection of the optical signal from a portion of the field of view bounded by the platform's boresight; correcting the first instance of the detected reflection; and resolving the content of a plurality of cells in the field of view up to the platform's boresight. The apparatus comprises a radome; an optical signal generator; an optical transmission channel; an optical receiver channel; and a plurality of electronics capable of receiving the representative signal and: correcting the first instance of the detected reflection; and resolving the content of a plurality of cells in the field of view up to the boresight from the corrected first instance of the reflection.

Abstract: The present invention provides a coherent radar system based on a modification of standard non-coherent radar without Moving Target Indication. Typical radars in this class are Navigation radars which are mass produced with low cost components. These radars utilize a magnetron in the transmitter which is a random phase device. In the present invention, the received signal is extracted just prior to amplitude detection process (where phase information is lost), and digitized using an analogue to digital converter providing coherent detection based on correlation between the transmitted pulse and the received signal.

Abstract: A microwave motion sensor for protecting an area comprises an oscillator configured to generate a plurality of microwave signals, a random pulse generator configured to set a random pulse period for each transmitted microwave signal, an antenna configured to transmit the microwave signals and to receive reflected signals, and a signal processor coupled to the antenna through other circuitry, said signal processor is configured to process the reflected signals to determine a presence of a moving object in the protected area.

Abstract: Ground clutter is effectively separated from true signals echoed by a cable in the flight path of an aircraft, by encoding a transmitted pulse wave in a radar system with at least one transmit (TX) coding sequence, so that received signals echoed by the cable on which the pulse is incident and associated ground clutter are orthogonal or separable from one another. The TX coding sequence is altered into two receive (RX) coding sequences one of which corresponds to the cable and the other to the ground clutter. The two RX coding sequences are then correlated with the received signals, thereby separating the true signals echoed by the cable from the associated ground clutter.

Abstract: A ranging and communication multifunction system including a transmission unit and a receiving unit, and integrates two functions of ranging and communication in which the transmission unit includes a transmission circuit, a carrier wave modification device, and a transmission antenna. The receiving unit includes a receiving circuit, a wave detector, a low noise amplifier, and a receiving antenna, and a data modulation performed in the transmission circuit uses a PPM system. Thus, the receiving circuit provides a ranging circuit and a communication separately, so that the demodulation processing of ranging and communication can be performed in parallel.

Abstract: Techniques to image life forms through obstructions and at long standoff ranges employ a radar system that simultaneously transmits a plurality of RF pulse trains having different transmission frequencies and receives returns of the RF pulse trains reflected from a life form target. The returns are processed to generate digital radar data associated with the transmission frequency of each RF pulse train. The digital radar data is segmented and averaged to generate a Doppler spectrum response associated with the transmission frequency of each RF pulse train. Target classification is performed using the Doppler spectrum responses to extract biometric data describing the life form target.

Abstract: A transmitting unit of a short-range radar includes a first pulse generating unit, a second pulse generating unit, an oscillator and a switch, and while complying with the spectrum mask specified for a UWB short-range radar, emits a predetermined short pulse wave not interfering with the RR prohibited band or the SRD band into the space. The first pulse generating unit outputs a first pulse having the width larger than the width of the short pulse wave in a predetermined period. The second pulse generating unit outputs a second pulse having the width corresponding to the width of the short pulse wave during the period when the first pulse generating unit outputs the first pulse.

Abstract: A method for acquiring targets within a search area using an electronic device is disclosed. The method involves partitioning a first acquisition time period into a plurality of range gates, simultaneously positioning one or more of the range gates within the search area during a search mode, and transmitting an energy pulse train. Upon receipt of a reflection of the transmitted pulse train, the method records a signal level of the reflected energy pulse train within the first acquisition time period. Based on the recorded signal level, the method advances one or more of the range gates by a prescribed outbound movement increment until the signal level within at least one of the range gates is above a prescribed acquisition signal level threshold.

Abstract: This disclosure provides a radar device including a transmission module for sequentially transmitting two or more kinds of pulse signals having different pulse widths by a predetermined transmitting pattern, a memory module for storing a predetermined number of pulse reply data corresponding to each kind of the pulse signals, the predetermined number being number of transmissions of the kind of the pulse signals, a pulse integrating module for performing pulse integration of the pulse reply data stored in the memory module for each kind of the pulse signal, and an image generating module for generating a radar image using the results of the pulse integration.

Abstract: A system and method are described for generating waveforms for use in radar and sonar systems. The system includes waveform generation circuitry a waveform generator and an up-conversion module. The waveform generator generates concatenated pulse waveforms at an IF band. In a given pulse repetition interval (PRI), the concatenated pulse waveforms comprise a first and second pulse types associated with first and second IF frequencies respectively. The up-conversion module up-converts the concatenated pulse waveforms to an RF band to form first and second sets of pulses. In the given PRI, each pulse is up-converted to a different RF frequency, pulses of different lengths are associated with a similar carrier frequency, and at least one pulse from each of the sets of pulses implements frequency diversity.

Abstract: A method for presence detection using a microwave transmitter and a microwave receiver, the method including generating a sequence of clock pulses by means of a pulse generator, feeding the clock pulses to a clocked circuit arranged to generate a sequence of first pulses of a first pulse length and a sequence of second pulses of a second pulse length, each one of the first and second pulse lengths being related to a predetermined number of the clock pulses, periodically actuating the microwave transmitter by means of the sequence of first pulses, periodically actuating the microwave receiver by means of the sequence of second pulses; and determining whether an object is present in the detection volume based on microwave radiation being received by the microwave receiver. A system for such presence detection is also disclosed.

Abstract: There is provided a distance measuring apparatus having system flexibility by varying a distance measuring range and a distance measuring resolution according to an environment and circumstance. The apparatus includes a reference pulse generator and a delay pulse generator capable of controlling frequencies of a reference pulse and a delay pulse and duty ratios of the reference pulse and the delay pulse. The reference pulse generator and the delay pulse generator include a programmable clock generation unit generating a clock of a frequency determined by a frequency control signal and a duty ratio control unit controlling a duty ratio of the clock generated by the programmable clock generation unit.

Abstract: A radar apparatus transmits a pulse signal including pulses having at least two different pulselengths in a specific transmit pulse pattern and receives a returning echo signal through a single antenna. A tuning voltage setting timing generator generates a timing of setting a tuning voltage according to a combination of transmission pulselengths and a tuning processor performs tuning operation in a manner suited to a current transmission pulselength based on the tuning voltage setting timing. The radar apparatus may include a tuning voltage alteration decider for deciding whether or not to alter the tuning voltage based on a combination of alternate pulselengths before altering the pulselength of the pulse signal generated by a transmitter and the tuning processor alters the tuning voltage based on the result of decision made by the tuning voltage alteration decider.

Abstract: A method for clutter filtering staggered pulse repetition time data signals is provided. The method comprises the steps of receiving a plurality of staggered pulse repetition time data signals. The data signals may comprise one or more desired signals and one or more clutter signals. The method further comprises separating the staggered pulse repetition time data signals into a first separated data sequence and a second separated data sequence. The first and second separated data sequences comprise equally spaced data samples. The method also comprises the step of filtering the one or more clutter signals from the first and second separated data sequences.

Abstract: Provided is a semiconductor device for a spread spectrum radar apparatus which suppresses spurious signals resulting from non-linearity of active elements. The semiconductor device as the inverse spread spectrum modulation unit for the spread spectrum radar apparatus has a coupled line of two lines and another coupled line of two lines. The semiconductor device includes: an unbalanced to balanced transforming circuit which converts a received signal inputted as an unbalanced signal into a balanced signal pair; a switch circuit having one or more transistors; and a balanced inverse spread spectrum circuit which obtains as differential signal PN signals belonging to the same sequence code as a PN code which is used to generate an original signal of the received signal, also obtains the balanced signal pair from the unbalanced to balanced transforming circuit, and performs inverse spread spectrum modulation on the balanced signal pair by the switch circuit using the PN codes inputted as the differential signal.

Abstract: A method of operating synthetic aperture radar in a low PRF mode, comprising generating a stream of radar pulses, imposing onto said stream a predetermined modulation of the Pulse Repetition Frequency (PRF), directing said stream to a target area, and processing received pulses, comprising separating the received pulses as a sequence of sets, and superposing received radar pulses of said sets, whereby to enhance the central received lobe and to attenuate side lobes.

Abstract: A system and method for warning a helicopter of an approaching bullet using existing sensor systems is disclosed. The disclosed method including the steps of: detecting and providing bearing information for detected small arms weapon firing locations near the helicopter, determining a detection area and detection time window for the fired bullet, determining the antennas of the RF transmitting and RF receiving systems covering the bearing of the detected weapon firing; determining a timing sequence and allocating time segments for transmitting and receiving RF signals during the detection time window, commanding the RF emitting system to emit and the RF receiving system to receive RF signals during their allocated time segments, processing RF signals received and determining whether reflected RF signal pulses from the emitted RF signal pulses are present, and outputting a warning where reflected RF signal pulses are detected.

Abstract: Marine radar systems and methods for producing low power, high resolution range profile estimates. Non-linear Frequency Modulation (NLFM) pulse compression pulses are frequency stepped to form a low power, wide-bandwidth waveform. Periodically, calibration filters are determined and applied to return signals for correcting non-ideal effects in the radar transmitter and receiver.

Abstract: A pulse radar is provided with a filter for eliminating a transmission waveform interfered with an answering signal from a received waveform, and a harmonic detector or a phase delay detector for detecting arrival and end of the answering signal reflected on a target.

Abstract: A multifunction detector for detecting energy reflected from the surface, the detector comprising: a focal plane array in communication with the optical receiving path; and an optical receiving path; a read-only integrated circuit in communication with the optical receiving path, integrated with a focal plane array; and a processor programmed to operate the focal plane array and read-out integrated circuit in a first mode to process signals in a first frequency band, and in a second mode to process signals in a second, wider frequency band.

Abstract: In a pulse radar ranging system, directional coupling means are configured to convey transmit pulses to be transmitted via an antenna to a target and to convey target echoes received by the antenna to a signal mixer that generates an intermediate frequency signal. To embed a reference measurement into the target measurement, the directional coupling means include a four-port circulator with an additional port arranged between a port receiving the transmit pulses and a port coupled to the antenna. A reference line is coupled to the additional port for generating reference echo pulses in response to input pulses. The circulator is configured to split a portion of the transmit pulses to the reference line and to convey there reference echo pulses to the antenna.

Abstract: A spread spectrum radar apparatus includes: a transmission unit which generates a spread signal that is a spectrum-spread signal, using a first oscillator signal, a second oscillator signal, and a transmission PN code, and which emits the spread signal as a detection radio wave; and a reception unit which receives, as a reception signal, the detection radio wave reflected from an object, and which generates an intermediate frequency signal by despreading the reception signal based on the first oscillator signal and a reception PN code obtained by delaying the transmission PN code.

Abstract: An architecture for a spread-spectrum transmitter-receiver system in an advanced tactical data link that allows the receiver to readily acquire and synchronize to a desired LPD signal. Signal acquisition is performed with a cyclic range search that uses multiple redundant known sequences mapped to a known message sequence in a highly repeated manner. By employing the invariance of the speed of light, and synchronicity between transmitter and receiver, the architecture can significantly reduce the computational complexity of the receiver. Additionally, the architecture enables ad hoc channel access, controlled latency, distance estimation, and distance-directed transmissions.

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 millimeter-wave transmitter-receiver uses an NRD guide as a fundamental configuration and includes a millimeter-wave signal oscillator, a pulse modulator, a circulator, an antenna and a mixer. In the millimeter-wave transmitter-receiver, a line length of a third dielectric guide is set so that ?=±? in which ? is a phase difference at a center frequency between a portion of a transmission millimeter-wave signal, which is reflected via a third dielectric guide on the leading end portion of the third dielectric guide and returned to leak to a third connecting portion of the circulator, and another portion of the millimeter-wave signal, which leaks from a first connecting portion to the third connecting portion of the circulator. It is possible to reduce the change in the mixer output and enhance the millimeter-wave transmission/reception performance.

Abstract: A distance measurement sensor and a distance measurement method using the same are disclosed. The distance measurement sensor can use all of a pulse method and a Continuous Wave (CW) method, can select an appropriate measurement method according to the distance to be measured, thereby accurately measuring the distance. The distance measurement sensor solves the reception-signal limitation caused by a transmission leakage signal in the case of the CW method, reduces an amount of power consumption, measures distances of several objects at the same time, and establishes the range of the distance.

Abstract: A multistatic detection device for measuring a distance to an object includes a transmitter and a receiver, each having a high-frequency oscillator and a pulse generator. The pulse generators can be supplied with synchronisation signals emitted by signals generators, the synchronisation signals being transmitted by a data bus common to the transmitter and the receiver. The relation of the deterministic phases of high-frequency signals can be produced by the high-frequency oscillator. The method includes feeding two synchronisation signals to the transmitter and the receiver by the common data bus, the transmitter signal is transmitted towards an object, the signal passing through the receiver and contained in the data bus being mixed with a reception signal reflected by the object, thereby producing a measuring signal thereby making it possible to compare the phases of clock signals.

Abstract: There is provided a device and method for detecting an overlap of pulse signals, capable of easily detecting a point where reference and delayed pulse signals overlap each other, and an apparatus for estimating a distance using the same. The device for detecting an overlap of pulse signals, the device detecting a point where first and second pulse signals having different frequencies begin to overlap each other, the device including: a duty adjustor generating a third pulse signal by increasing a duty of the second pulse signal; a pulse signal calculator multiplying the first and second pulse signals by the third pulse signal, respectively and adding respective results together to output a signal; and an overlap determiner determining a middle of a pulse with a greatest width in the signal outputted from the pulse signal calculator as a point where the first and second pulse signals overlap each other.

Abstract: A pulse radar ranging system having a measurement channel and a reference channel is described. In the measurement channel containing an antenna and a measurement target, the normal measurement is performed by processing an echo from the target. In the reference channel containing signal delay means, a reference echo is processed to obtain temperature compensation information.

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 device includes: an impulse generator that generates an impulse; a transmission antenna that transmits the impulse generated by the impulse generator; a reception antenna that receives a reflected signal of the impulse transmitted from the transmission antenna and reflected by the object, and a leakage signal of the impulse transmitted from the transmission antenna; and a distance calculator that calculates the distance to the object, based on the time difference between the reflected signal and the leakage signal received by the reception antenna.

Abstract: A radar system comprising a transmit antenna, a receive antenna and a mixer for combining a signal received by said receive antenna with a reference signal to produce an output signal. The transmit antenna includes an active antenna oscillator, the reference signal being derived from the active antenna oscillator. The active antenna oscillator is turned on and off by a pulse modulated biasing signal to produce a pulse modulated RF signal. The reference signal is delayed before being supplied to the mixer, the output of the mixer being used to determine when a detected object is a pre-determined distance from the system.

Abstract: Disclosed is a distance measuring system comprising a transmitter that sequentially generates pulse sequences each having a plurality of pulse signals of equal amplitudes arranged at equi-time intervals, and transmits the generated pulse sequence as a radio wave; and a receiver that receives the pulse sequence transmitted from the transmitter as a radio wave, and has a distance calculator that acquires propagation times of the pulse signals in the received pulse sequence, and calculates a distance from the transmitter by giving different weightings to the pulse signals for the propagation times acquired for the respective pulse signals. As the amplitudes of the pulse signals in the received pulse sequence become larger, the weightings are made larger.

Abstract: A pulse radar system includes: a pulse output circuit that outputs a periodic transmission pulse and a gate pulse having a cycle which is a rational multiple of a cycle of the transmission pulse and is different from a cycle of the transmission pulse; a transmission circuit that generates and sends a transmission pulse wave based on a transmission pulse from the transmission circuit; a transmission antenna that radiates a transmission pulse wave from the transmission circuit; a reception antenna that receives a reception pulse wave reflected from an object in transmission pulse waves from the transmission antenna; a reception circuit that demodulates a reception pulse wave from the reception antenna and outputs a reception pulse; and an extracting circuit that extracts and outputs a reception pulse synchronizing with a gate pulse from the pulse output circuit, among reception pulses from the reception circuit.

Abstract: A pulse radar is provided with a filter for eliminating a transmission waveform interfered with an answering signal from a received waveform, and a harmonic detector or a phase delay detector for detecting arrival and end of the answering signal reflected on a target.

Abstract: A modulated pulse wave requires a pulse width of 1 nsec or less, but it is difficult that a PIN diode, which is conventionally used treats such a modulated pulse wave with narrow pulse width. In order to solve such a problem, it is an object to provide a pulse modulator, which outputs a modulated pulse wave with narrow pulse width and a pulse wave radar device, which can output a modulated pulse wave with narrow pulse width. In order to achieve this operation, the pulse modulator and the pulse wave radar device of the present invention differentiate a pulse from a pulse generating circuit so as to generate a differentiated wave with narrow width, and switch an oscillated wave from an oscillating circuit according to the differentiated wave so as to output a modulated pulse wave with narrow pulse width.

Abstract: The invention relates to a system, device, and method for using radar signals to measure the distance (h) to a surface from said device, the device comprising a transmitter and a transmitting antenna for transmitting radar signals, and a receiver and a receiving antenna for receiving a radar signal. The device may also comprise a first additional reflecting object separate from the receiving antenna, which additional reflector is designed so as to introduce a first predetermined alteration in radar signals upon reflection, with the device being equipped with means to differ between received signals with and without said predetermined alteration. The first predetermined alteration introduced by the first separate reflector can be, for example, a modulation shift or a shift in the polarization of the signal. In a typical embodiment the additional reflector is located close to the radar unit creating a double transition from radar unit to the surface.

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.