Rca Inc.

Sperry Corporation

Henry C Johnson

Ronald W Kipp

A frequency synthesizer of the phase-locked loop type, having an output circuit circuit which produces an output signal at any of a plurality of alternating frequency values depending on the value of a command signal applied to the output circuit. The synthesizer includes a storage apparatus for storing, for each frequency value, an indication of the precise command signal value which causes the frequency to be produced. When the frequency is again to be produced the stored signal is used to rapidly drive the output circuit to produce the desired frequency

Frequency synthesizer with learning circuit

A ranging radar of the radio frequency (RF) frequency modulated-continuous wave (FM-CW) type transmits an RF FM-CW signal to a reflecting surface at an unknown range R from the radar. The reflecting surface reflects the signal to a modulating device. The modulating device further modulates the signal at a frequency F which is high in comparison to the modulating frequency of the FM-CW signal. The further modulated signal is transmitted by the device to the reflecting surface and back to the ranging radar where it is subtractively mixed with a sample of a transmitted signal. The mixed signal is at frequency F amplitude modulated by a beat frequency, the period of which corresponds to range R. The frequency F is removed from the mixed signal leaving the beat frequency signal from which is determined range R.

Ranging radar including a modulating reflector

An adjustable alternating signal having a desired period, P, is applied to a cycle counter arranged to count n cycles and applied to a timer arranged to time out n.multidot.P after a first cycle is applied to the counter and timer. A comparator is coupled to the counter and timer to determine whether the counter reaches its count of n cycles first or whether the timer times out first indicating that the period of the alternating signal is shorter or longer, respectively, than desired. An integrator is responsive to the signal from the comparator for changing the alternating signal which achieves the desired period.

Digital discriminator for determining frequency error of an oscillator

An interrogating station includes apparatus for transmitting a frequency modulated signal having a relatively low modulation rate to a plurality of uniquely tagged targets and for receiving therefrom a further modulated reply signal at a relatively high modulation rate, a mixer for mixing the transmitted and reply signals, to produce range modified tag modulation frequencies for all tagged targets, a voltage controlled filter for selectively passing the mixer output signal corresponding to any one of the tagged targets and a sweep and hold circuit for providing the frequency selecting voltage to the filter. The frequency selecting voltage is caused to change when no signal is passed by the filter and is fixed at the voltage corresponding to the signal frequency when a signal is passed by the filter. The magnitude of the frequency selecting voltage when fixed is used to determine the identity of the tag and the signal passed by the filter is further processed to determine range and/or range rate of the associated target.

Interrogating radar for use with tagged targets

A frequency-modulated continuous wave (FM-CW) ranging system for determining the range of a target includes apparatus which utilizes a target simulating delay line and target illuminating antenna, alternately switched to a difference frequency determining circuit and a scaling device to compensate for undesired changes of the FM modulation waveform.

FM-CW Radar ranging system with automatic calibration

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 oscillators together to inject lock the voltage controlled oscillator to the frequency of the reference oscillator when no transmitting is occurring.

Pulse radar transmitting oscillator

A radar, such as a ranging radar, includes a non-scanning antenna which directs a beam of microwave energy toward and receives a return beam from a microwave reflector. A microwave reflector is mounted to a movable platform. As the platform moves, the microwave beam is scanned along a desired object. In one application, the heighth of a non-flowing material in different parts of a container is measured.

Scanning radar

A frequency-modulated continuous wave (FM-CW) ranging system includes apparatus which utilizes a target simulating delay line and scaling device to compensate for undesired changes of the FM modulation waveform.

FM-CW Radar ranging system

A signal processor for monotonic FM-CW ranging system having reduced quantization error. The difference signal from FM-CW radar is applied to two cascaded phase locked loops (PLL). The second PLL is modified for unidirectional frequency tracking.

Monotonically ranging FM-CW radar signal processor

A frequency-modulated continuous wave (FM-CW) ranging system wherein continuous feedback to the FM oscillator of the system eliminates drift in frequency excursions of the FM waveform.

Stabilizing and calibration circuit for FM-CW radar ranging systems

An electronic calibrator for doppler radar speed sensors and odometers comprising a variable impedance device, such as a varactor, positioned in the near-field of the radar antenna to modulate the radar probe beam, in the calibrate mode of the radar at a rate corresponding to the frequency of a doppler signal that would be sensed by the radar in its operating mode at a given speed. The impedance during the calibration mode is excited by a separate a.c. signal at a frequency corresponding to the doppler signal frequency. The output of the radar provides an indication during the calibration mode that can be adjusted to a calibrated indication corresponding to the actual speed causing a doppler signal of the same frequency as the excitation signal for the impedance.

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Neshanic, NJ, United States of America

Henry C Johnson