Patents Assigned to MONOLITH INC.
  • Patent number: 4902925
    Abstract: A reflectionless surface acoustic wave transducer is proposed which has first and second opposed conductive transducer pads on a substrate of piezo-electric material. A plurality of groups of n interdigitated .lambda./4 electrodes extend from the opposed pads to form an elongated transducer. Each group of n interdigitated electrodes has a spacing within the group of .lambda./4 and the spaces between adjacent groups of the interdigitated electrodes are .lambda./2 such that adjacent groups cancel reflections from each other thereby establishing a reflectionless surface acoustic wave transducer.
    Type: Grant
    Filed: March 15, 1988
    Date of Patent: February 20, 1990
    Assignee: R.F. Monolithics, Inc.
    Inventor: Peter V. Wright
  • Patent number: 4888589
    Abstract: A digital-to-analog converter (DAC) ladder segment is disclosed in which diode networks are introduced into the ladder step circuits. Each diode network includes a control diode which controls the flow of current through the network in accordance with a signal from an associated actuating circuit, which in turn is controlled by an input digital signal. In one embodiment, the control diodes are connected in series with resistors, with the diodes and resistors scaled so that their respective bit circuits conduct desired current levels. In another embodiment, the control diodes have equal scalings and are connected in series with respective resistors and second diodes which are called so that their step circuits conduct the desired currents. In a third embodiment, current sources are provided which supply currents to the second diodes in amounts that permit the second diode and the resistors for the various step circuits to have substantially equal scalings.
    Type: Grant
    Filed: June 9, 1988
    Date of Patent: December 19, 1989
    Assignee: Precision Monolithics, Inc.
    Inventor: Derek F. Bowers
  • Patent number: 4761616
    Abstract: 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.
    Type: Grant
    Filed: September 4, 1987
    Date of Patent: August 2, 1988
    Assignee: R. F. Monolithics, Inc.
    Inventor: Darrell L. Ash
  • Patent number: 4757274
    Abstract: An improved input current compensation circuit is provided for a dual branch amplifier, particularly an amplifier employing superbeta transistors. The compensation circuit has a superbeta compensation transistor which is matched with the superbeta amplifier transistors, a bipolar transistor connected across the superbeta transistor in a manner analogous to a voltage limiting circuit in the amplifier section, and current sources which provide operating currents to both the superbeta and bipolar compensation transistors. The base current of the superbeta compensation transistor is mirrored to the bases of the superbeta amplifier transistors, and the superbeta transistors, bipolar transistor and current sources in the compensation section are scaled relative to corresponding elements in the amplifier section so that the superbeta amplifier transistor base currents are substantially compensated by current mirrored from the compensation circuit.
    Type: Grant
    Filed: January 14, 1987
    Date of Patent: July 12, 1988
    Assignee: Precision Monolithics, Inc.
    Inventor: Derek F. Bowers
  • Patent number: 4749964
    Abstract: 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.
    Type: Grant
    Filed: December 8, 1986
    Date of Patent: June 7, 1988
    Assignee: R. F. Monolithics, Inc.
    Inventor: Darrell L. Ash
  • Patent number: 4731595
    Abstract: A surface acoustic wave resonator device having a resonant cavity formed on a substrate between a transducer and its related grating that causes a symmetric frequency response with one major resonant frequency response and low spurious frequency responses, with no etched grooves or recessed electrodes, with a minimum electrode geometry of .lambda./4, with single level fabrication and uniform wave velocity throughout the structure and being frequency insensitive to electrode reflections.
    Type: Grant
    Filed: January 24, 1986
    Date of Patent: March 15, 1988
    Assignee: RF Monolithics, Inc.
    Inventor: Peter V. Wright
  • Patent number: 4694266
    Abstract: A notch filter which utilizes a quadrature coupler with the input signal on one of its four terminals, a first tuned surface acoustic wave device coupled to a second on of the terminals for receiving the input signal at 0.degree. phase shift, a second tuned surface acoustic wave device coupled to a third one of the terminals for receiving the input signal with a 90.degree. phase shift and the fourth terminal being utilized as the output signal terminal.
    Type: Grant
    Filed: July 29, 1986
    Date of Patent: September 15, 1987
    Assignee: R. F. Monolithic, Inc.
    Inventor: Peter V. Wright
  • Patent number: 4687984
    Abstract: An active load circuit for operational amplifiers and the like is described which provides an improved common mode rejection ratio and common mode voltage range, and alleviates transistor saturation and cut off problems during maximum slew rates. Drive currents from the operational amplifier or other circuit are transmitted directly through respective load resistors, thereby reducing voltage offsets which degrade common mode rejection ratio. At the same time the absolute voltage levels at the operational amplifier or like circuit are reduced, thereby increasing the common mode voltage range. A pair of active load transistors are supplied with current from current sources independent of the amplifier transistors, and deliver their respective currents to the same resistors which receive the amplifier currents. An output is taken from one of the load transistors without connecting to either of the amplifier transistors.
    Type: Grant
    Filed: May 31, 1984
    Date of Patent: August 18, 1987
    Assignee: Precision Monolithics, Inc.
    Inventor: James R. Butler
  • Patent number: 4683423
    Abstract: A test socket for a leadless chip carrier is disclosed in which a clamp is pivotally mounted to a base member, such that the carrier can be inserted into a recess in the base member and the clamp pivoted closed to lock the carrier in place. The clamp includes a set of arms which engage corresponding brackets on the base to progressively secure the carrier and chip as the clamp is rotated either clockwise or counterclockwise. The clamp makes direct contact with the chip to assure a good electrical connection with underlying electrical contact springs.
    Type: Grant
    Filed: October 30, 1985
    Date of Patent: July 28, 1987
    Assignee: Precision Monolithics, Inc.
    Inventor: William D. Morton
  • Patent number: 4682224
    Abstract: 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.
    Type: Grant
    Filed: October 31, 1983
    Date of Patent: July 21, 1987
    Assignee: R. F. Monolithics, Inc.
    Inventors: Lawrence H. Ragan, Clinton S. Hatmann, Darrell L. Ash
  • Patent number: 4682223
    Abstract: 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.
    Type: Grant
    Filed: October 31, 1983
    Date of Patent: July 21, 1987
    Assignee: R. F. Monolithics, Inc.
    Inventors: Lawrence H. Ragan, Clinton S. Hartmann, Darrell L. Ash
  • Patent number: 4677369
    Abstract: A temperature insensitive voltage reference is described which can advantageously be implemented using standard CMOS processing techniques. A pair of parasitic bipolar transistors are coupled with appropriate resistors to produce a voltage with a temperature coefficient that is equal in value but of opposite polarity to a zener diode voltage-temperature coefficient. This voltage is then combined with a zener diode voltage to yield the desired output reference voltage.
    Type: Grant
    Filed: September 19, 1985
    Date of Patent: June 30, 1987
    Assignee: Precision Monolithics, Inc.
    Inventors: Derek F. Bowers, Ali Tasdighi
  • Patent number: 4675561
    Abstract: A CMOS output drive circuit has two field effect transistors (FETs) implemented with a CMOS process and characterized by parasitic bipolar transistors. The back-gates of the two transistors are tied together, such as by forming the devices in a common well, and the back-gate of the second FET is also connected to prevent its associated parasitic bipolar transistor from conducting. Quiescent loads are applied to the two FETs so that their voltages are comparable during low output loading, resulting in a drive circuit with high input impedance and high output voltage swing. The output terminal is taken from the first FET, the voltage of which becomes unbalanced from the second FET at relatively high output loads, turning on the parasitic bipolar transistor for the first FET. This gives the drive circuit a desirably high input impedance and low output impedance for heavy output loads.
    Type: Grant
    Filed: November 15, 1985
    Date of Patent: June 23, 1987
    Assignee: Precision Monolithics, Inc.
    Inventor: Derek F. Bowers
  • Patent number: 4670680
    Abstract: A Quartz Crystal for surface acoustic wave device application defined by the Euler angles lambda (.lambda.) equal about 45.degree. and mu (.mu.) equal about 55.degree. with an acoustic wave propagation direction angle theta (.theta.) equal plus about 10.degree. to minus about 30.degree..
    Type: Grant
    Filed: July 29, 1986
    Date of Patent: June 2, 1987
    Assignee: R. F. Monolithics, Inc.
    Inventor: Jeffrey C. Andle
  • Patent number: 4670681
    Abstract: An ST cut quartz crystal for surface acoustic wave device application defined by the Euler angles lambda (.lambda.) equal about 0.degree., mu (.mu.) equal about 132.75.degree. and with an acoustic wave propagation direction theta (.theta.) equal about plus or minus 25.degree..
    Type: Grant
    Filed: July 29, 1986
    Date of Patent: June 2, 1987
    Assignee: R. F. Monolithics, Inc.
    Inventor: Peter V. Wright
  • Patent number: 4663664
    Abstract: 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.
    Type: Grant
    Filed: October 31, 1983
    Date of Patent: May 5, 1987
    Assignee: R. F. Monolithics, Inc.
    Inventors: Lawrence H. Ragan, Clinton S. Hartmann, Darrell L. Ash
  • Patent number: 4633165
    Abstract: A temperature compensated voltage reference circuit in which a compensation current is generated by establishing a current through a passive impedance element which varies with temperature in accordance with the transistor voltage equation. This current is proportionately reflected into the output impedance circuit associated with the voltage reference, where it compensates for temperature induced voltage variations. The passive impedance element is adjustable to correct for processing variations, and the compensation circuit requires no voltage supplies other than those typically provided for the reference circuit by itself.
    Type: Grant
    Filed: August 15, 1984
    Date of Patent: December 30, 1986
    Assignee: Precision Monolithics, Inc.
    Inventors: Steven M. Pietkiewicz, Derek F. Bowers
  • Patent number: 4616197
    Abstract: A resonator, resonator filter having an output transducer of typical design and conductance response and an input transducer whose conductance response can be adjusted to offset adverse conductance response of said output transducer thereby providing a unique improved overall conductance response of the resonator, resonator filter.
    Type: Grant
    Filed: December 5, 1985
    Date of Patent: October 7, 1986
    Assignee: R. F. Monolithics, Inc.
    Inventor: Peter V. Wright
  • Patent number: 4599587
    Abstract: An impedance element formed from a single-port, surface acoustic wave transucer which generates a conductance versus frequency response characteristic having first and second peaks separated by a valley at a predetermined frequency and which generates a susceptance versus frequency response characteristic having a substantially constant portion over a finite bandwidth on both sides of said predetermined frequency.
    Type: Grant
    Filed: December 3, 1984
    Date of Patent: July 8, 1986
    Assignee: R. F. Monolithics, Inc.
    Inventors: Clinton S. Hartmann, Peter Wright
  • Patent number: 4583051
    Abstract: An output circuit amplifier has first and second stage amplifying transistors with an impedance circuit connected between the base of the first stage transistor and the collector-emitter circuit of the second stage transistor to draw current from the first stage transistor base, thereby keeping both transistors out of saturation. The impedance circuit establishes a voltage drop between the two transistors such that large output voltage swings are enabled at an output terminal connected to the second stage transistor. The collector-emitter circuit of the first stage transistor is connected directly to a positive voltage bus to avoid further saturation problems.
    Type: Grant
    Filed: November 6, 1984
    Date of Patent: April 15, 1986
    Assignee: Precision Monolithics, Inc.
    Inventor: Derek F. Bowers