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Patent No. 5979328

Vehicular Impact Signaling Device


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Class 342/199 - Automatic frequency control (AFC)

Subclass of Class 342 - Communications: directive radio wave systems and devices (e.g., radar, radio navigation)
Definition: Subject matter wherein the circuitry is provided to maintain
No. of patents: 50
Last issue date: 12/04/2012

NumberTitleIssue Date
8325085Weather radar signal processing
A method and system are described whereby a magnetron-based radar transmission signal is accurately measured, allowing for measurement of absolute phase change returns from fixed clutter targets caused by changes in the refractive index of the transmission medium.
7446699Error corrector for radar timing systems
A feedback loop corrects timing errors by reducing deviations from a constant radar sweep rate. Errors are detected and fed back to a phase corrector in a high gain feedback system. A precision radar rangefinder can be implemented with a direct digital synthesizer (...
7412013Start-up automatic frequency control (AFC) method and apparatus
A method and apparatus for use in connection with wireless communication to adjust the frequency of an oscillator to synchronize with a received signal by correlating a synchronization code channel with training sequences to estimate positive and negative offsets wh...
7355484Oscillator and radar apparatus using the same
An oscillator and a radar apparatus that includes a resonator electro-magnetically connected to a micro strip line and a rotor connected to the resonator by capacitance. The bottom surface of the rotor has a changing height in the circumferential direction of the ro...
7340280Method of configuring base station, and base station
A base station and a method of configuring a base station are provided in a cellular telecommunication system, wherein the base station comprises an electrically tunable duplex filter with a tuning range covering at least two parallel sub-bands used in the telecommu...
7312855Combined coherent and incoherent imaging LADAR
A long range eye-safe laser radar (LADAR) system for use in an environment where real-time non-cooperative identification of an object is required. In particular, a laser beam is aimed at an object, the laser energy reflected from the object is collected by a detect...
7236547Start-up automatic frequency control (AFC) method and apparatus
Method and apparatus for adjusting the frequency of a voltage controlled oscillator (VCO) at a receiver to synchronize the receiver with the transmitter by correlating a synchronization code channel with training sequences to estimate positive and negative offsets w...
7187732Start-up automatic frequency control (AFC) method and apparatus
7139530Method and apparatus for calibrating a reference oscillator
A method and apparatus for calibrating a reference oscillator and use of a calibrated reference oscillator is disclosed. To gain cost reduction advantages, a less accurate reference oscillator is utilized in a wireless communication device. The cost benefit is gaine...
7019684Phase lock loop circuitry
An arrangement for reducing the effect of vibration-induced changes in phase of the first local oscillator in a tracking receiver wherein final detection is accomplished by a synchronous detector in a phase lock loop incorporating a voltage-controlled oscillator is ...
6630903Programmable power regulator for medium to high power RF amplifiers with variable frequency applications
A power regulator regulates the power provided to a transistor-based circuit, such as that which might be employed in a high stability MTI radar system. According to the invention, a variable reference voltage is controlled based on the frequency of opera...
6597308Radar apparatus
A modulation signal generation circuit performs frequency modulation of a VCO with a triangular wave for operation as an FM-CW radar. A signal processing circuit gives a modulation signal for detection generated from the modulation signal generation circu...
6577270Radar transceiver
A compact millimeter wave radar transceiver at low cost is provided wherein a direct current voltage applying circuit is coupled to a high frequency line to apply a fast pulse wave without losing a sharp input pulse pattern. A voltage is applied to a nega...
6532271Carrier recovery and doppler frequency estimation
Method and system for carrier recovery and estimation of Doppler shift from a signal source that is moving relative to a signal receiver. A pure carrier preamble for the received signal is processed through each of two stages of a linear predictor to obta...
6147560Method and device relating to supervision and control of an oscillator signal
The present invention relates to methods and devices for such control and supervision of an oscillator signal from a controllable oscillator that is done mainly to control the frequency variation of the oscillator signal. According to the invention, the c...
6072427Precision radar timebase using harmonically related offset oscillators
Two crystal oscillators are configured as a "plug-and-play" precision transmit-receive clock that requires no calibration during manufacture. A first crystal oscillator generates a transmit clock and a second crystal oscillator operates at a small offset ...
6057798Apparatus and method for frequency modulation
A method and apparatus for frequency modulating a continuous wave signal is shown to comprise a voltage-controlled oscillator (VCO) having a first and a second control loop to maintain the carrier frequency of such VCO at a frequency determined by a cryst...
5790068AFC control switching circuit
An automatic frequency control loop for maintaining a center carrier freqcy fed to a notch filter for blocking out system reverberation includes, along with the conventional elements found in an automatic frequency control loop, a control switching circu...
5751195Circuit to indicate phase lock in a multimode phase lock loop with anti-jamming security
A lock detection circuit for a phase lock loop circuit having a phase lock loop circuit, generally a series circuit of a detector, a filter and a VCO with a PLL input terminal and an output terminal. A test circuit is coupled to the phase lock loop and in...
5694132Voltage feedback linearizer
Apparatus for linearizing the sweep frequency output of an FMCW radar employing a voltage controlled oscillator includes means for comparing a series of reference voltages sequentially with the instantaeous oscillator drive voltge, accumulating the indivi...
5654716Circuit for short duration multiple look pulse based frequency measurement
A low cost automatic frequency control system measures short duration radio frequencies with high a degree of accuracy within 0.5 MHz. The system is programmable to allow applicability over a wide range of frequencies within the required accuracy and vari...
5497402Automatic frequency control device for satellite communications ground system
The present invention relates to an automatic frequency control device and an automatic gain control device which have the advantage of improving the efficiency of a system with very low signal-to-noise ratio by compensating for frequency error generated ...
5408239Method for setting search band widths of a GPS receiver
In a GPS receiver which searches for a satellite radio wave over a predetermined search bandwidth while setting a search center frequency fs to a start point, an offset value of Ɗfosc of an oscillator calculated last when a power so...
5151703Method and apparatus for improved automatic fequency control
The frequency of a variable frequency oscillator in a pulsed radar is adjusted using samples of an IF signal. An initial frequency adjustment is made using a sample taken during RF transmission. This initial adjustment contains an inaccuracy introduced by...
5107272Radar system employing injection locked transmitter stage
A radar transmitter chain employing injection locked oscillator, e.g., a magnetron, as an output stage. Problems arise with maintaining the injection locking bandwidth centered on the radar source transmit frequency. This alignment is maintained by allowi...
4983978Multi-frequency comb generator for radar and the like
A multi-frequency comb generator (2-4; FIG. 1) for radar and the like using a feedback loop through a frequency multiplier, such as for example, a doubler (3). A reference or master oscillator output goes through a directional coupler (2), for example, a ...
4982195Servo control with self calibrating preset
A frequency input for receiving a frequency signal and digital storing for storing the received frequency signal. A controller has a first and second input and an output. The first input is connected to the digital storage for providing a reference signal...
4823133Radar system
The invention relates to a radar system comprising a transmitter with a periodically tunable HF-transmitter tube, as a magnetron with rotating tuning body, and a receiver with a mixing stage, in which echo pulses caused by transmitted radar pulses are mix...
4809004Crystal controlled magnetron
The invention comprises a weather radar system in which a magnetron transmitter is controlled in frequency by injecting therein a low power locking signal from a stable frequency source. Frequency lock between the source and the magnetron is maintained wi...
4626856Radar signal correction system
A radar correcting system has features for providing a corrected radar receiver reflection to a Doppler process unit. The corrected receiver pulse accounts for variances in phase, amplitude and frequency of the transmit pulses. The system has a phase dete...
4600889Coherent oscillator
A coherent oscillator circuit which samples a signal responsive to phase and frequency of a transmitted pulse of radio frequency energy in an acquisition mode, and regenerates a signal corresponding to the sampled phase and frequency in a save mode is dis...
4600924Automatic frequency control for radar receiver
A digital automatic frequency control for a pulse-type radar receiver having a voltage controlled local oscillator. A first digital number is generated and converted to a first analog voltage for coarse control of the local oscillator frequency. The first...
4591859Radar transmitter
A radar transmitter is shown to include a voltage-controlled oscillator and associated amplifier to produce a signal to be transmitted with any noise generated within such oscillator and amplifier being reduced to a minimum by extracting a sample of the s...
4510622High sensitivity millimeter-wave measurement apparatus
A millimeter wave measurement apparatus utilizing a phase-locked transmitter to generate a millimeter wave-signal and a phase-locked local oscillator receiver to receive the transmitted millimeter wave signal. A conventional microwave receiver unit receiv...
4330760System for correlating the operating frequencies of two variable-frequency microwave generators
Two variable-frequency microwave generators, i.e. a coaxial magnetron producing outgoing waves and a voltage-controlled oscillator emitting a heterodyning signal for incoming waves of a radar transceiver, are continuously tuned by a pilot signal modifying...
4241345Pulse radar transmitting oscillator
An oscillator circuit for use in a pulsed radar transmitter includes a reference oscillator of one frequency of, a voltage controlled oscillator controlled to transmit a radio frequency at a different frequency, and a switch for connecting the two oscilla...
4238796Radio frequency pulse generator
A radio frequency pulse generator for use in a pulsed radar transmitter includes a reference oscillator of one radio frequency, a second oscillator producing a different second radio frequency which differs from a multiple M of the first frequency by a gi...
4228434Radar receiver local oscillator control circuit
An improved automatic frequency control arrangement for a missile-borne inverse receiver is shown to include a reference oscillator and a voltage-controlled oscillator with control means for the latter, such means including a frequency-to-voltage converte...
4179694Frequency control systems
An AFC system for a radar comprising means for changing in one sense a control voltage fed to a voltage controlled local oscillator forming part of the radar receiver when a predetermined number of cycles of a difference frequency between a local oscillat...
4159475VCO-Controlled phase lock system
A phase coherent canceller for jamming suppression is provided with a variable controlled oscillator which is locked in frequency and phase to a reference local oscillator in a closed loop configuration....
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