Raytheon Company

Magnavox Consumer Electronics Company

The Magnavox Company

Magnavox Electronic Systems Company

Robert D Streeter

Lee A McMillan

Roderick G Bergstedt

John G Mohr

Roland C Luetzelschwab

James R Weigand

A circuit for matching the impedance of an output load to an active device includes a transformer including a first winding having a terminal for coupling to the output of the active device and a second winding electromagnetically coupled to the first winding, and a plurality of taps, each of the plurality of taps having a first end coupled to a position on the second winding corresponding to a ratio of the second winding to first winding differing from other ones of the plurality of taps, and a second end. The matching circuit further includes a plurality of MEMS switches each having a control input for receiving a corresponding control signal, a first terminal coupled to the second end of a corresponding one of the plurality of taps, and a switched output selectively coupled to a matching junction in response to the corresponding control signal.

Mems-tuned high power, high efficiency, wide bandwidth power amplifier

A MEM relay includes an actuator, a shorting bar disposed on the actuator, a contact substrate, and a plurality of liquid metal contacts are disposed on the contact substrate such that the plurality of liquid metal contacts are placed in electrical communication when the MEM relay is in a closed state. Further, the MEM relay includes a heater disposed on said contact substrate wherein said heater is in thermal communication with the plurality of liquid metal contacts. The contact substrate can additionally include a plurality of wettable metal contacts disposed on the contact substrate wherein each of the plurality of wettable metal contacts is proximate to each of the plurality of liquid metal contacts and each of the wettable metal contacts is in electrical communication with each of the plurality of liquid metal contacts.

Microelectromechanical micro-relay with liquid metal contacts

A MEM relay includes an actuator, a shorting bar disposed on the actuator, a contact substrate, and a plurality of liquid metal contacts are disposed on the contact substrate such that the plurality of liquid metal contacts are placed in electrical communication when the MEM relay is in a closed state. Further, the MEM relay includes a heater disposed on said contact substrate wherein said heater is in thermal communication with the plurality of liquid metal contacts. The contact substrate can additionally include a plurality of wettable metal contacts disposed on the contact substrate wherein each of the plurality of wettable metal contacts is proximate to each of the plurality of liquid metal contacts and each of the wettable metal contact is in electrical communication with each of the plurality of liquid metal contacts.

A single pole, double throw micro-electromechanical (MEM) switch. The inventive switch includes a first contact providing a first terminal of the switch. A second contact provides a second terminal of said switch. A cantilever beam provides a third terminal of the switch. The inventive switch includes a system for electrostatically pushing or pulling the beam to disengage the first contact and engage the second contact. In an illustrative implementation, the system for electrostatically operating the switch includes a first charge storage structure on the beam, a second charge storage structure on the switch, and an electrical supply for creating an electrical charge on the first and the second charge storage structures. The first and second charge storage structures are effective to create a force of repulsion therebetween on the application of an electrical charge thereto. The 'pull' electrostatic force closes the MEM switch. The 'push' force aids in opening the switch. The 'push' capability is the result of the use of like (same polarity) electrostatic charges on the control surfaces. The like charges provide an electrostatic repulsion force during the switch opening process.

Method and apparatus for an improved single pole double throw

A method, device and circuit which applies an electrostatic repulsion pushing force to a MEM switch armature during an opening process. The repulsive force adds to the spring restoration force on the armature, increasing the opening speed of the switch and aids in overcoming stiction effects. The inventive switch includes a contact electrically connected to a first terminal of the switch. A throw is electrically connected to a second terminal of the switch. Finally, a mechanism is provided for opening the switch by electrostatically causing the throw to disengage the contact. In the illustrative implementation, the mechanism for opening the switch includes a first charge storage structure mounted on the throw and a second charge storage structure mounted in proximity to the first charge storage structure. When charges are applied between the first and the second charge storage structures, a force of repulsion is created or a force of attraction is created depending on the polarity of the potential.

Method and apparatus for an improved micro-electrical mechanical switch

An amplitude modulated RF amplifier using dual path modulation to increase operating efficiency. Both the RF drive to the amplifier and the DC power supply voltage to the amplifier are amplitude modulated. Preferably, the power supply modulation is accomplished with a high efficiency pulse width modulator circuit. To prevent phase shift distortion, the modulated DC output from the power supply is used both to power the RF amplifier and to amplitude modulate the RF drive to the amplifier. For maximum efficiency, the modulators are both non-linear. Maximum efficiency is realized with primarily supply modulation and some drive modulation providing the positive envelope modulation and primarily a non-linear RF drive modulation providing the negative envelope modulation. The use of primarily RF drive modulation for the deep negative modulation will reduce the amount of incidental phase modulation experienced, while having a nearly inconsequential effect on total efficiency of the RF amplifier.

Apparatus and method for generating an amplitude modulated RF signal

A circuit for processing an angle modulated signal having amplitude modulation signal components in stereophonic broadcasting systems. An inverse modulation of a signal to be detected is provided over a first signal amplitude range, and a constant signal level is provided over a remaining range for signals having a marginal amplitude level. The discontinuity in the control range avoids noise expansion for high negative amplitude modulator levels for the signal to be angle modulated.

Signal processor for AM stereophonic receiving apparatus

A receiver for demodulating a stereophonic broadcast signal. Envelope detection is provided for a preselected radio frequency broadcast signal. Angle demodulation of a difference signal contained in the broadcast signal is provided at the radio frequency level avoiding the use of superheterodyne techniques. Improved linearity is achieved over detection techniques which operate at an intermediate frequency level. Receiver protection from excessive negative modulation peaks is provided as well as subsequent audio signal processing.

Receiving apparatus for stereophonic broadcast having amplitude and

A digital detector for a 5 Hz signal is combined with a detector for Manchester encoded data with a frequency of 2.5 Hz. The preferred apparatus includes a signal generating means in the form of an oscillator which generates a signal of a known frequency higher than that of the 5 Hz signal. This oscillator is connected to a frequency responsive means and to the circuit in which 2.5 Hz and 5 Hz signals are to be detected. The frequency responsive means produces an output signal in response to the generation of a given number of cycles of said higher frequency signal during one half of any cycle of said predetermined low frequency signals. Also connected to the frequency responsive means and to the circuit in which the predetermined low frequency signals are to be detected is a detection signal means. This produces a detection signal in response to the reception of an output signal from the frequency responsive means and a signal indicating the end of a half cycle of either the 2.5 Hz or 5 Hz signal.

Low frequency tone detector

A superheterodyne receiver is described for demodulating signals containing both amplitude and angle modulation components. An intermediate frequency signal is produced which is simultaneously amplitude detected as well as angle demodulated. Detector means are provided for detecting the occurrence of high negative amplitude modulation peaks of the broadcast signal. During high negative amplitude modulation peaks, the angle demodulator output is held at a fixed level until the amplitude of an input signal is restored to a predetermined minimum level.

Circuit for demodulating amplitude and angle modulated broadcast signals

Apparatus is described for transmitting and receiving stereophonic broadcasts in the low frequency commercial AM broadcast band. A transmitter is described which modulates the phase and amplitude of a broadcast signal with separate information signals. A pilot tone may also be included to identify the transmission as stereophonic. Receiving means for detecting the PM and AM components to derive separate signals for stereophonic reception are included.

Low frequency AM stereophonic broadcast and receiving apparatus

Apparatus is described for removing stereophonic signals contained in a broadcast signal. Removal of a stereophonic indicator tone frequency on the broadcast signal is also provided. Separate outputs measuring both a summation signal of left plus right audio signals and a difference signal of left minus right audio signals are provided. Matrix means are also included for separating left audio signal and right audio signal from the summation and difference signals. These recovered audio signals may be monitored by standard broadcast instruments to observe the performance level of the broadcast signal.

Modulation monitor for AM stereophonic broadcasts

A voltage controlled frequency source has an output frequency which varies in accordance with primary power line frequency variations. The output frequency of the voltage control frequency source is used to control the rate at which data is fed into a teleprinter machine thereby providing the teleprinter with data at a rate that can be varied in accordance with power line frequency variations. A method of modifying input data rate into a teleprinter machine in accordance with frequency variations of the primary power line frequency is also provided.

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Fort Wayne, IN, United States of America

Robert D Streeter