Rf Monolithics, Inc.

Texas Instruments Corporation

Darrell Lee Ash

Lawrence H Ragan

Clinton S Hartmann

Benjamin P Abbott

Clinton S Hatmann

An apparatus includes a first oscillator configured to generate a reference signal and a second oscillator configured to generate an output signal having a controllable frequency. The apparatus also includes a frequency difference detector configured to generate a difference signal having a frequency based on a frequency difference between the reference signal and the output signal. The apparatus further includes a discriminator configured to modify the frequency of the output signal based on the difference signal. The frequency difference detector can be configured to generate the difference signal having multiple pulses. The discriminator can be configured to count a number of pulses in the difference signal during a specified time period and to modify the frequency of the output signal based on the counted number of pulses. The specified time period can be adjustable.

Frequency-locked synthesizer with low power consumption and related system and method

A frequency agile sequential amplifier circuit that includes first and second RF amplifiers coupled by a SAW delay line, a double balanced mixer coupling the first RF amplifier to the SAW delay line, the output of the first RF amplifier providing a signal as a first input to the double balanced mixer and a variable pulse generator coupled to both said first and second RF amplifiers to cause them to sequentially and alternately conduct, and a divide/2 circuit coupling said variable pulse generator to said double balanced mixer as a second input at &#xbd; the rate of said RF amplifiers to cause the sequential amplifier circuit to achieve frequency agility and to substantially maintain its sensitivity.

Frequency agile RF circuit

A two port, single pole SAW resonator is employed for a local oscillator to eliminate the secondary frequency responses of the prior art without adding additional inductances and capacitances within an amplifier stage. The stray capacitance which is seen within the equivalent circuit of a single pole, two port SAW resonator at a port for the SAW resonator is tuned out by coupling an appropriately sized inductance in parallel with that stray capacitance. Access to the series resonator within the SAW resonator equivalent circuit is thus provided, permitting direct tuning of the resonant frequency for the SAW resonator. The high Q of the SAW resonator ensures low phase noise/edge jitter, while direct tuning of the series resonator enables a wide tune range. The tunable SAW resonator circuit is thus well-suited for use in a low phase noise tunable oscillator employed, for instance, in clock recovery within SONET applications.

Low phase noise, wide tune range saw oscillators and methods of operating the same

To secure the benefits of a low phase noise, wide tune range SAW oscillator in noisy environments, the tunable two port SAW resonator circuit within the oscillator is employed in differential mode, connected to a differential amplifier circuit to create a differential oscillator. In the absence of any need for ground or power supply voltage level references, low phase noise/edge jitter is maintained even in hostile environments while providing sufficient tune range to track small frequency changes. The resulting differential mode SAW oscillator is thus well-suited for use, for instance, in clock recovery within SONET applications.

Noise resistant low phase noise, frequency tracking oscillators and methods of operating the same

A crystal-controlled oscillator circuit is modified by the present invention by replacing the crystal with the first signal port of a two-port SAW resonator filter that has a low-loss primarily inductive characteristic and taking the oscillation output from the other port of the filter to provide an oscillator frequency with harmonics that are reduced significantly when compared to the output of a crystal-controlled oscillator.

Feedback oscillator circuit using a saw resonator filter

A transceiver including a receiver having a sequential amplifier that includes at least first and second RF amplifier stages coupled together by a delay line. A transmitter in the transceiver includes an oscillator for generating an RF carrier and the oscillator includes the delay line as a phase shifting element. A modulator is coupled to the oscillator for modulating the RF carrier either AM, OOK modulated, FM, FSK modulated, PM, and PSK modulated.

Receiver/transmitter having common elements

A sequential amplifier having at least two amplifier stages separated by a delay device such that a clock may control both stages to energize one while the other is de-energized, thus allowing a signal to be amplified by adjacent amplifier stages without the adverse effects of feedback associated therewith.

Sequential amplifier

A sequential amplifier having at least two amplifier stages separated by a delay device such that switching means may energize either or both amplifier stages at any given time to obtain maximum gain of the input signal so long as no oscillations occur between stages, thus allowing a signal to be amplified by adjacent amplifier stages without the adverse effects of feedback associated therewith.

A voltage controlled oscillator circuit having an amplifier coupled in series with a feedback circuit and having adjustable voltage means coupled to the phase shifting element means for varying the phase shift of the phase shifting element output signal thereby varying the frequency of oscillation of the oscillator circuit.

Voltage controlled oscillator

A phase shift oscillator formed with a surface acoustic wave coupled resonator in series with an amplifier and wherein the coupled resonator has a substantially 180.degree. phase shift occurring between the 3dB points of the frequency response curve of the coupled resonator.

Coupled resonator phase shift oscillator

A superregenerative detector utilizing a single transistor and having a surface acoustic wave device in the feed back loop coupling the output to the input to cause oscillation wherein the surface acoustic wave device is a low loss delay line formed as a single phase unidirectional transducer on a quartz substrate.

Superregenerative detector having a saw device in the feedback circuit

A method of descrambling received video program signals with transmitted synchronization signals for use in a video receiver comprising the steps of providing first terminals for receiving the scrambled video signal and second terminals coupled to the video receiver and connecting an electronic ticket containing descrambling circuitry to the first terminals for receiving and descrambling the received video signal and coupling the descrambled video signal from the electronic ticket to the second terminals for transfer to the video receiver.

Descrambler unit method and apparatus for television signal descrambling

A system for providing intelligible video program signals and corresponding video synchronization signals to authorized video displays only comprising transmitting means for transmitting scrambled signals of at least one video program; a receiver for receiving said scrambled video program signals for said at least one video program; and a descrambling unit coupled to said receiver and including an electronic ticket removably coupled to the input of said video receiver for intercepting and descrambling the at least one scrambled video program signal from said receiver and recovering the synchronizing signals, and means coupling the recovered synchronization sweep signals and the unscrambled intelligible video program signals to said video display.

System, method, and apparatus for television signal scrambling and

An electronic ticket for descrambling transmitted video program and synchronization signals for use in a video receiver comprising first terminals for receiving the scrambled video signals, a descrambling circuit having its input coupled to the first terminals and producing at least a partially descrambled signal at its output, second terminals for coupling the descrambled signal to the video receiver and enclosing portions of the first and second terminals, and the descrambling circuit in a unitary package whereby the ticket can be used as a plug-in unit.

Growing community of inventors

Sachse, TX, United States of America

Darrell Lee Ash