Abstract: Technologies are provided for clockless physically unclonable functions (PUFs) in reconfigurable devices. Embodiments of the disclosed technologies include processing circuitry configured to perform numerous operations. The operations can include receiving a challenge continuous pulse signal, and generating a response continuous pulse signal by iteratively extending the challenge continuous pulse signal in time-domain. In some configurations, the iteratively extending includes generating a next continuous pulse signal by operating on a prior continuous pulse signal according to a stretching function, and generating a second next continuous pulse width signal by operating on the next continuous pulse signal according to a folding function.

Abstract: Sensors coupled to a vehicle are calibrated, optionally using a dynamic scene with sensor targets around a motorized turntable that rotates the vehicle to different orientations. One vehicle sensor captures a representation of one feature of a sensor target, while another vehicle sensor captures a representation of a different feature of the sensor target, the two features of the sensor target having known relative positioning on the target. The vehicle generates a transformation that maps the captured representations of the two features to positions around the vehicle based on the known relative positioning of the two features on the target.

Abstract: A method is disclosed that can include the steps of: in response to a radar stimulator aircraft receiving information for causing it to stimulate a radar system in a user specified manner, the radar stimulator aircraft monitoring the position of an onboard unit thereof relative to at least one antenna of the radar system; and based on the received information and the monitored position of the onboard unit the radar stimulator aircraft controlling its flight and the emission of radar signals thereby to stimulate the radar system in the user specified manner.

Abstract: The present disclosure relates to a method in which a radar apparatus for a vehicle detects a mounting angle and the radar apparatus for a vehicle, and more particularly, to a method for detecting a mounting angle of a radar apparatus for a vehicle using a power ratio of signals acquired by transmitting signals having different directivity angles and the radar apparatus for a vehicle.

Abstract: The system (1) is used for the automatic calibration of an imaging-antenna arrangement (2) using an evaluation unit (4). The antenna arrangement (2) transmits signals (6) and receives the signals (6?) reflected from a calibration object (3) of known shape. The calibration object (3, 31, 32) provides at least one diffuse reflector (8). In the evaluation method, position coordinates of the calibration object (3) are entered, and the following method steps are implemented after the measurement of the reflected signals (6?): i. Calculation of the reflections of the calibration object (3, 31, 32), ii. Calculation of calibration data, iii. Preparation of an image of the calibration object with the use of the calibration data, iv. Determination of corrected position coordinates by evaluating the image of the at least one diffuse reflector, v. Implementation of steps i. to iv. with corrected position coordinates.

Abstract: An antenna system (10) comprises a transmitter part (12) comprising n inputs (40.1 to 40.n) to the antenna system, a transmitter part antenna array 18 comprising k radiating elements; a respective beam-forming network (20.1 to 20.n) connected to each of the n inputs with each beam-forming network having a plurality of outputs; and k signal combiners (22.1 to 22.k) each having a plurality of inputs and a respective output. Each output of each beam-forming network is connected to a respective input of each of the signal combiners and the output of each signal combiner is connected via an output stage to a respective one of the k radiating elements. The beam-forming networks are configured such that each of the transmitter part inputs is associated with a respective transmitter part beam (24.1 to 24.n) having a respective beam-width.

Abstract: Disclosed herein is a radar calibration system for vehicles. The radar calibration system for vehicles includes a target simulator receiving a radar signal through a reception antenna, delaying the received signal through a delay line, and transmitting the delayed signal through a transmission antenna, and a radar apparatus transmitting the radar signal to the target simulator through a transmission antenna, receiving the delayed signal from the target simulator through a plurality of reception antennas, calculating phase differences among the delayed signals received through the plurality of reception antennas, and generating and storing phase correction values of reception channels of the plurality of reception antennas to correct the calculated phase differences.

Abstract: A method for measuring certain parameters of the impulse response of a propagation channel involving emitters and reflectors that are fixed or mobile, and for detecting and determining the parameters regarding the position and kinematics of the emitters and reflectors, or for auto-locating the reception system implementing the invention, in a system comprising N sensors receiving signals from the emitters or from the reflection on the reflectors. The method determines an ambiguity function which couples the spatial analysis and the delay-distance/Doppler-kinematic analysis, and determines at least one sufficient statistic ?(l,m,K) corresponding to the correlation between the known signal s(kTe) corresponding to the complex envelope of the signal emitted and the output of a filter w(l,m) where l corresponds to a temporal assumption and m corresponds to a frequency assumption.

Abstract: An optical modulator comprising an input suitable to receive an optical carrier, and two Mach-Zender modulators in parallel, which constitute two different optical paths, the whole circuit constituting a third Mach-Zender modulator, the optical modulator being characterized in that: the first Mach-Zender modulator is provided with an electrode suitable to carry two signals, each obtained by the sum of the two tones fR and fD, of equal power but dephased of ?/2, and with an electrode for realizing a Single Side Band modulation of the tones fR and fD; the second Mach-Zender modulator is biased by means of a DC electrode; the third Mach-Zender modulator comprising an electrode suitable to realize the reversal of the optical carrier phase of the signals deriving from the first and the second Mach-Zender modulator, so as to suppress the optical carrier and thus obtaining only the tones fR and fD in the optical spectrum.

Abstract: Systems and methods of providing error tolerant robust simplex wireless data for systems employing time correlated data transfer are provided. In one embodiment, a system comprises: sensors that produce samples of time correlated data; and a node coupled to the sensors by a wireless link. The link comprises a primary stream for simplex transmission of data packets, and a secondary stream for simplex transmission of delayed data packets, the delayed data packets a delayed retransmission of the time correlated data. When the node receives a first data packet from a first sensor via the primary stream, the data receiving node check validity. When the first data packet is corrupted, the node validity checks a second data packet received via the secondary stream. When both packets contain corrupted data, the node builds a reconstructed plurality of sequential time correlated data samples based on non-corrupted data samples from within the data packets.

Abstract: A simulation device and a system and method for using the simulation device are disclosed. The simulation device may contain a plurality of antenna elements positionable on or near a radar or other sensing device. The simulation device may be configured to control the plurality of antenna elements to transmit signals that simulate a reflection of an electromagnetic signal off of one or more targets of particular sizes at particular azimuths, elevations, distances, trajectories, and/or velocities.

Abstract: A method and system are provided for testing antenna systems using position determination, orientation determination, test pattern analysis using a variety of factors and equipment including positions and orientation of antenna(s) under test at specific points and signal processing systems.

Abstract: A system for testing radar in accordance with one embodiment comprising a target motion platform; a target motion platform controller for controlling motion of the platform; a radar responsive tag and a delay line located on the target motion platform; the radar which is being tested; and a motion measurement simulator for inputting data to the radar electronics assembly to simulate movement of the radar. In some embodiments the system further comprises a radar motion platform, wherein the radar electronics assembly is positioned on the radar motion platform; a radar motion platform controller for controlling the movement of the radar motion platform; and a master controller coupled to the radar motion platform controller and the target motion platform controller.

Abstract: A method for determining changes in internal delays of RF units, the RF units including a plurality of receivers and transmitters. The method includes providing initial direct signals' time of arrivals of the RF units initial internal delays of the RF units. Following this, each transmitter transmitting a direct signal, and the real-time direct signal's time of arrivals of the RF units, are measured. Then, changes in internal delays of the RF units are calculated based on the real-time direct signals' time of arrivals and initial direct signals' time of arrivals. And finally, real-time internal delays of the RF units are calculated based on the changes in internal delays and the initial internal delays of the RF units.

Abstract: A millimeter wave radar target simulation system and method. The system includes a down-converter that converts a millimeter wave radar signal to an intermediate frequency, an electrical-to-optical modulator that modulates an optical signal based on the down-converted signal, an optical-to-electrical demodulator that demodulates an optical signal to an electrical signal, an optical delay line serving to delay a signal passing from the electrical-to-optical modulator to the optical-to-electrical demodulator, and an up-converter that converts the electrical signal from the optical-to-electrical demodulator to a frequency that simulates a millimeter wave target return.

Abstract: The radar system includes: a transmission circuit transmitting the radar waves via a transmission antenna; a receiving circuit receiving the reflected waves via a receiving antenna; a delay line having an end connected to aid transmission circuit and the other end connected to said receiving circuit, which delays the radar waves by a predetermined delay amount; a correlation circuit/coherent detection circuit which detects a waveform having a strength equal to or higher than a predetermined strength, from a signal provided from said receiving circuit which obtains the signal from the reflected waves or the delayed radar waves; and a level decision circuit which judges, during self-diagnosis, whether or not the detected waveform is a waveform of the delayed radar wave according to the predetermined delay amount, and if the waveform is not the waveform of the delayed radar wave, determines that abnormality occurs in said radar system.

Abstract: A millimeter wave radar target simulation system and method. The system includes a down-converter that converts a millimeter wave radar signal to an intermediate frequency, an electrical-to-optical modulator that modulates an optical signal based on the down-converted signal, an optical-to-electrical demodulator that demodulates an optical signal to an electrical signal, an optical delay line serving to delay a signal passing from the electrical-to-optical modulator to the optical-to-electrical demodulator, and an up-converter that converts the electrical signal from the optical-to-electrical demodulator to a frequency that simulates a millimeter wave target return.

Abstract: A method of delaying propagation of a radio frequency (RF) signal through a circuit is described. The method comprises receiving data that represents a delay time interval, providing an RF signal when a start pulse triggers a memory device, initiating a count through the delay time interval based on receipt of a start pulse, and outputting the RF signal after the delay time interval has expired.

Abstract: A method of delaying propagation of a radio frequency (RF) signal through a circuit is described. The method comprises receiving data that represents a delay time interval, providing an RF signal when a start pulse triggers a memory device, initiating a count through the delay time interval based on receipt of a start pulse, and outputting the RF signal after the delay time interval has expired.

Abstract: A system for testing radar in accordance with one embodiment comprising a target motion platform; a target motion platform controller for controlling motion of the platform; a radar responsive tag and a delay line located on the target motion platform; the radar which is being tested; and a motion measurement simulator for inputting data to the radar electronics assembly to simulate movement of the radar. In some embodiments the system further comprises a radar motion platform, wherein the radar electronics assembly is positioned on the radar motion platform; a radar motion platform controller for controlling the movement of the radar motion platform; and a master controller coupled to the radar motion platform controller and the target motion platform controller.

Abstract: The invention relates to a device and a method for simulating a radio channel, wherein a signal transmitted and received by more than one antenna is simulated. The method comprises supplying an input signal of each antenna to a similar delay line, each delay line comprising a delay element connected in series for each propagation path, weighting an output signal of the delay elements corresponding with each propagation path by a term in dependence of a control vector of each transmitting antenna, by a term describing the distortion of a propagation path, and by a term in dependence of a control vector of each receiving antenna, and adding up the components corresponding with each receiving antenna and obtained from the outputs of the weighting means.

Abstract: A system for testing radar in accordance with one embodiment comprising a target motion platform; a target motion platform controller for controlling motion of the platform; a radar responsive tag and a delay line located on the target motion platform; the radar which is being tested; and a motion measurement simulator for inputting data to the radar electronics assembly to simulate movement of the radar. In some embodiments the system further comprises a radar motion platform, wherein the radar electronics assembly is positioned on the radar motion platform; a radar motion platform controller for controlling the movement of the radar motion platform; and a master controller coupled to the radar motion platform controller and the target motion platform controller.

Abstract: Systems and methods are provided for simulating a target platform. An incoming radar signal is transmitted from a radar source and is received at a first platform. Time of the received radar signal is modulated to generate first and second range extent signals. The first range extent signal is vector modulated, and the second range extent signal is divided into a plurality of divided second range extent signals. A first of the plurality of divided second range extent signals is phase modulated. A second of the plurality of divided second range extent signals is amplitude modulated. The modulated signals are transmitted from the first platform.

Abstract: The present invention relates to a monitoring device (1) with a transmitter unit (2) and a receiver unit (3) for monitoring an area. Slotted cables serve as antennas. According to the invention, a first slotted cable is arranged as a transmitting an antenna (4) for transmitting a pulsed high-frequency signal and a second slotted cable is arranged as a receiving antenna (9) for receiving the reflected signal. The slotted cables are arranged in association with each other and essentially parallel to each other, and the transmitter unit (2) is connected to the first slotted cable at one end of the antenna arrangement and the receiver unit (3) is connected to the second slotted cable at the other end of the antenna arrangement.

Abstract: A positioning method, which is related to a technique to measure a correct position of a terminal by preventing time required for the position measurement, of calculating a position of a receiver according to signals from a plurality of wireless transmitters includes a first step of measuring propagation delay time of the signal from each of the wireless transmitters and calculating a position of the receiver and a standard deviation about measuring distance error, a second step of calculating a positioning error of the receiver a third step of determining, according to the positioning error calculated by the second step, wireless transmitters in directions nearer to a direction in which the positioning error is large, and a fourth step of re-detecting signals from the wireless transmitters determined by the third step and thereby re-calculating the position of the receiver.

Abstract: A method and system for signal processing, especially useful as a signal repeater, i.e. for simulating the characteristic echo signature of a preselected target. The system has a digital radio frequency memory (DRFM) and associated circuitry, including digital tapped delay lines, and a modulator in each delay line to impose both amplitude and frequency modulation in each line.

Abstract: A device for generating a desired transit time delay of a pulsed radar signal is characterized in that a delay line (13) with signal input and signal output for the pulsed radar signal is provided whose transit causes time delay &tgr; of the pulsed radar signal, that a signal amplifier (14) is connected downstream of the delay line which increases the amplitude of the pulsed radar signal by a certain amplification factor f, and that a decoupling device (12) is provided which permits supply of at least part of the amplitude of the pulsed radar signal coming from the signal output of the signal amplifier to the signal input of the delay line again and which permits, after n times transit of the pulsed radar signal through the delay line, decoupling of at least part of the amplitude of the pulsed radar signal, wherein T=n·&tgr; and wherein n is a natural number.

Abstract: A radar system and a characteristic adjustment method for the radar system are provided, in which a control voltage waveform of a voltage controlled oscillator for frequency-modulating a sending signal can be set in a short time without increasing the required amount of memory. In adjusting time-varying characteristics of a voltage signal for frequency modulation on a voltage controlled oscillator determining a sending frequency, the time-varying characteristics of the voltage signal for frequency modulation are adjusted to optimize a form of a protrusion in signal intensity included in a frequency spectrum of a beat signal.

Abstract: A radar test system for testing the performance of an automotive radar system includes circuitry for multiple down and up conversions of a signal from the automotive radar. Conditioning circuitry is further included to delay an intermediate frequency signal (IF2) obtained after the second down conversion to simulate the delay of a return signal from an object located a particular distance from the automotive radar system, and to attenuate the IF2 signal to simulate variable target sizes, and to generate a Doppler shift in the IF2 signal to simulate target speed. The conditioned signal is up-converted and transmitted back to the automotive radar system to determine if the automotive radar provides accurate readings for distance, size and speed.

Abstract: A device for generating a desired transit time delay of a pulsed radar signal is characterized in that a delay line (13) with signal input and signal output for the pulsed radar signal is provided whose transit causes time delay &tgr; of the pulsed radar signal, that a signal amplifier (14) is connected downstream of the delay line which increases the amplitude of the pulsed radar signal by a certain amplification factor f, and that a decoupling device (12) is provided which permits supply of at least part of the amplitude of the pulsed radar signal coming from the signal output of the signal amplifier to the signal input of the delay line again and which permits, after n times transit of the pulsed radar signal through the delay line, decoupling of at least part of the amplitude of the pulsed radar signal, wherein T=n·&tgr; and wherein n is a natural number.

Abstract: A method and apparatus is provided for remotely and constantly calibrating a transponder by using the ring around phenomenon. A number of different time varying physical quantities, such as for example temperature, signal level, noise, transmission line flex, frequency, and general operational effects, affect the inherent delay in transponders on a time varying basis. The invention relies on a the ring around phenomenon to produce pulse doublets, wherein the distance between the pulses in the pulse doublets correspond to the instantaneous delay in the transponder. The system is configured so that instantaneous variation in the transmission delay is detected and recognized on a pulse by pulse basis and transmitted to the interrogation device, which then functions to calculate the actual delay. Normal operation of the transponder is not affected by the continuous calibration method, and therefore a special calibration mode is not required.

Abstract: A radar target with delayed reply means. The radar target contains devices for: (a) receiving a radar signal which has a frequency of from about 0.5 to about 94 gigahertz, (b) phase coherently amplitude modulating a continuous wave light emission with the radar signal with the frequency of from about 1 to about 94 gigahertz, (c) delaying an amplitude modulated light pulse for at least about one radar pulse width, (d) detecting the delayed modulated amplitude modulated light pulse, (e) converting a detected amplitude modulated light pulse into a converted radio frequency pulse, (f) modulating the converted radio frequency pulse, thereby producing a delayed modulated radio frequency pulse, and (g) transmitting the delayed modulated radio frequency pulse.

Abstract: A linear phase detector circuit enables locking of two frequency sources which can operate in the range of 10 GHz with a minimal frequency offset, such as from 0 Hz to 50 KHz. With the frequency sources operating at frequencies F1 and F2 with an offset F2−F1 or F1−F2, the phase detector generates a DC signal indicating a phase offset between a signal F2−F1 or F1−F2 derived from the frequency sources and a reference operating at the desired offset F2−F1 or F1−F2, while eliminating any 2(F2−F1) or 2(F1−F2) component. In this way, the phase detector allows a substantially higher loop bandwidth than the offset F2−F1 or F1−F2, and allows phase tracking independent of the offset. The phase locking circuitry is useful in applications such as providing a variable Doppler shift in a radar signal.

Abstract: An automated simulator for radar and sonar applications. The inventive simulator is implemented in hardware and generates current parameters with respect to a simulated target in response to a plurality of initial values with respect thereto. In the illustrative embodiment, the initial values include range, velocity, and acceleration and are stored in first, second and third register respectively. In the best mode, the invention is implemented in a field-programmable gate array. The inventive target simulator also includes a range delay circuit for generating a simulated return from the simulated target. The range delay circuit includes logic for determining whether a simulated pulse train to be received is ambiguous or unambiguous and adjusting the pulse repetition rate of the pulse train accordingly. The range delay circuit calculates die initial time that a packet needs to make the trip to and from the target.

Abstract: A system is disclosed for generating simulated radar targets that eliminates the necessity for large outdoor test ranges and is relatively low in cost. The simulated radar target generating system provides complex targets of given simulated dimensions at given simulated distances when stimulated by signals emitted by the radar sensor in the sensor's operational frequency. The dimensions are simulated by the use of multi-tap delay device while the distances (or, range) are simulated by routing the signal, in the form of light, through a fiber optic delay of a desired length. This system, which costs less than $50 thousand, can be located as close as eight feet to the sensor under test.

Abstract: There is provided an image rejection mixer for downconversion of an incoming signal to a lower intermediate frequency signal, using the absolute difference of frequencies between the incoming signal and the local oscillator signal. The image rejection mixer is set up to accept and downconvert incoming signals at two discrete frequencies f.sub.h and f.sub.l, where the local oscillator frequency is positioned mid-way between those frequencies f.sub.h and f.sub.l. There are two signal paths in the image rejection mixer, either one or the other of which is chosen by positioning a controllable single pole, double throw switch into one of its two switch positions. The output of the switch is led to a mixing element, from which an intermediate frequency signal is derived.

Abstract: A test beacon for a radar system includes: a first antenna for receiving a search signal and transmitting a processed search signal, a second antenna for receiving a tracking signal and transmitting a processed tracking signal, a first signal processor for shifting the phase of the received search signal and adjusting it to a predetermined level, a third signal processor for shifting the phase of the received tracking signal and adjusting it to a predetermined level, a search/tracking signal delaying unit for receiving the search and tracking signals phase-shifted by the first and third signal processors, delaying the signals for a predetermined time period, and distributing and outputting the delayed signals, a second signal processor for receiving the delayed search signal and filtering a frequency band of the search signal and adjusting the signal to a predetermined level, a fourth signal processor for receiving the delayed tracking signal and filtering a frequency band of the tracking signal and adjusting

Abstract: A moving target simulator for testing a radar system has a radio frequency receiver, a digital radio frequency memory in electrical communication with the radio frequency receiver for storing a signal received thereby, a digital delay circuit in electrical communication with the digital radio frequency memory for providing a time delay between reception and transmission of the radio frequency signal, an amplitude modulation circuit in electrical communication with the digital radio frequency memory for modulating an amplitude of the radio frequency signal, a Doppler modulation circuit in electrical communication with the digital radio frequency memory for providing a Doppler-modulated signal, and a radio frequency transmitter for transmitting the radio frequency signal after it has been delayed, amplitude-modulated, and/or Doppler-modulated.

Abstract: Interferoceivers are apparatus which use optical fiber loop based radio frequency (RF) signal train generators to store transient pulses and regenerate their identical replicas for analysis. The present invention further advances the art of RF signal train generators and interferoceivers in investigating acoustical, electromagnetic, and optical transient phenomena. The disclosure includes mechanisms for tuning the interferoceivers, and means for forming synthetic images with chaotic pulses or pulses of opportunity.

Abstract: There is disclosed a method and apparatus for verifying the integrity of a smart antenna system. A signal simulator replicates the respective signals received at the multiple sensors of the antenna array, with signal parameters that include the correlated effects of Doppler, delay and angular spread. A combination of hardware and software capabilities simulate a primary line-of-sight signal, plus reflected signals and refracted signals, which requires manipulation by the smart antenna processor to extract the temporal and spatial information of the signals of interest. The simulated signals may be varied in numbers, amplitude, phase, delay and bearing components for representing a variety of terrain, environmental, equipment and capacity conditions encountered in alternative environments and conditions. The output of the smart antenna processor is checked against the input parameters to compare, verify and calibrate the smart antenna system.

Abstract: A radar test system for testing a collision avoidance radar system. The radar test system includes circuitry to downconvert a signal from the collision avoidance radar to an intermediate frequency signal, to delay the intermediate frequency signal to simulate the delay of a return signal from an object located a particular distance from the collision avoidance radar system, and to upconvert and transmit the intermediate frequency signal back to the collision avoidance radar system to determine if the collision avoidance radar system provides accurate distance readings. The radar test system further couples the intermediate frequency signal to a spectrum analyzer. The spectrum analyzer can be used to determine if the collision avoidance radar system is operating within the 76-77 GHz frequency band allocated by the Federal Communications Commission (FCC). The radar test system further couples the intermediate frequency signal to a power meter.

Abstract: The electromagnetic target generator of this invention is used to simulate radar target for the purpose of testing and experimenting on a variety of weapon systems radars. The weapon system radar being tested emits a radar signal which is received by the target generator. The target generator delays, doppler shifts, and reemits the signal for receipt by the weapon system antenna. The simulated target presented to the radar system under investigation has digitally controlled range, radial velocity, coordinated doppler and radar cross section. This provides a realistic radar target return without requiring real targets. The radar system is exercised in inflight and tactical operational configuration and no part of the weapons system radar is bypassed. Delayed radar target replicas are indistinguishable from real target waveforms. The electromagnetic target generator may be used in locations which preclude the use of real radar targets, such as anechoic chambers, and also may be used in the field.

Abstract: A photonic radar decoy (50) is provided which simulates an aircraft to a radar having an interrogating signal. A plurality of receiving antenna (52, 54, 56, 58, 60) are attached to the decoy (50) with each of the receiving antenna (52, 54, 56, 58, 60) independently capable of receiving the interrogating signal from the interrogating radar system. Each signal received by an antenna (52, 54, 56, 58, 60) is transmitted to a signal combiner and amplifier (82) by delay lines (72, 74, 76, 78, 80). The combiner and amplifier (82) coherently adds the transmitted signals, thereby producing a coherent signal which is amplified and subsequently emitted by a non-directional transmission antenna 106, simulating a dynamic and complex radar signature of an aircraft.

Abstract: A near field planar wavefront generation method that uses a relatively small number (three to five) of transmitting antennas disposed a predetermined distance from an antenna array having a multi-wavelength aperture that is part of a system under test. The method creates a synthesized one-dimensional linear planar wavefront of radiation over at least ten wavelengths for testing the antenna array of the system under test. The planar wavefront is formed at a specific frequency and at predetermined distance from the transmitting antennas, typically in the range of from 100 to 200 feet. The transmitting antennas synthesize a plane wave with linear phase progression to simulate tilt variations. To achieve this, electromagnetic energy signals emitted by the respective transmitting antennas are amplitude and phase weighted to synthesize the one dimensional linear plane wave to produce a combined wavefront having a linear phase front across the aperture of the antenna array of the system under test.

Abstract: New apparatus comprise a optical fiber based RF signal train generator for storing transient RF pulses and regenerating the identical replicas for analysis. The apparatus further comprise RF receivers to process one stored pulse with a reference to other stored pulse. The present invention drastically increases our abilities to investigate acoustical, electromagnetic, and optical transient phenomena.

Abstract: A radar target simulator for generating simulated targets used in testing a radar system. Simulated targets are generated out of the radar system noise. The radar system includes a radar receiver coupled to a receive antenna. The simulator has an input for sampling a transmitted output signal from the radar system. A first reference oscillator is provided for generating a first reference signal, and a first mixer is coupled to the first reference oscillator for mixing the first reference signal with the sampled signal from the radar system to provide a simulated target signal. A laser is coupled to the first mixer for generating a light output signal that corresponds to the simulated target signal. A plurality of selectable delay paths that each have a different predetermined delay length are coupled to the laser. A photodetector is coupled to the plurality of delay paths for convening the light output signal derived from a selected one of the delay paths into a radio frequency (RF) simulated target signal.

Abstract: The calibration apparatus (16) includes a recirculating optical delay loop (22) constituted by two delaying fibers (F2, F3), an optical amplifier (28), and a coupler (26) for providing a succession of a plurality of delayed optical signals (OR) in response to a single initial signal (OA). The invention is particularly to radars.

Abstract: A radar target generator is disclosed which is not merely a simulator, generating video information for viewing by an operator, but is designed to be used in conjunction with an operating radar system, actually producing high fidelity radar targets, rather than targets that merely look like radar targets. Thus, it may be used for training of radar operators, as well as for calibrating, maintaining, and evaluating multiple types of radar systems. The system includes a first tap for sampling a portion of the radar signal traveling through a transmission line and redirecting that sample into the radar target generator. There, a central processor applies a target signature component to the sampled radar signal portion, following which a second tap returns the modified radar signal portion to a return radar signal traveling thorough a second transmission line.

Abstract: A radio frequency pulse multiplier for producing coherent multiples of radio frequency (rf) pulses comprising an input terminal for receiving rf pulses, a signal divider for providing a plurality of pulses in response to an input pulse, the output of the signal divider coupled to a plurality of signal paths, each respective path comprising a time delay element providing a selectable delay to a respective pulse, a signal combiner for combining the plurality of pulses on a single output, and an output terminal. The output of the multiplier comprises pulses delayed by amounts equal to the preselected delays in the respective signal paths of the multiplier. The multiplier may comprise signal conditioning elements for conditioning the rf pulses within the multiplier.

Abstract: New apparatus comprise a comprises an optical fiber based RF signal train generator for storing transient RF pulses and regenerating the identical replicas for analysis. The apparatus further comprise comprises an RF receivers receiver to process one stored pulse with a reference to other another stored pulse. The present invention drastically increases our abilities to investigate acoustical, electromagnetic, and optical transient phenomena.