Abstract: The invention is a microphonics suppression means for a high frequency resonant cavity. The resonant cavity is used in a RF oscillator to generate UHF/VHF frequencies. The resonant cavity comprises an outer wall portion, a center conductor portion, a tuning slug and a plurality of coupling probes. The coupling probes, tuning slug and center conductor are held in a fixed relationship by a microphonics suppression means made of a low dielectric material which fits over and around the center conductor and encapsulates the coupling probes and collars the tuning slug. The microphonics suppression means reduces the effect of microphonics on the output signal of the RF oscillator, thus allowing a clean output signal suitable for high power applications.

Abstract: Apparatus is provided for containing information designating the frequency of operation of a synthesized radio frequency receiver. The apparatus is programmable and selectively addressable with respect to operating frequency.

Abstract: The integral interconnect socket and flexible board assembly accepts an electronic module having a plurality of leads arranged in a predetermined pattern. The assembly includes a flexible printed circuit (PC) board having a plurality of conductors and a first set of holes disposed to respectively intersect the conductors. A substantially rigid platform is mounted to the PC board and has a second set of holes. The first and second set of holes are in alignment and define common apertures arranged in the predetermined pattern to receive the leads of the modules. A layer of metal plating formed within the apertures makes electrical connections with the respective conductors. Jacks are mounted to each aperture for receiving the leads and making electrical connections between the leads and the conductors.

Abstract: A quadrature combiner circuit is provided which employs a quadrature coupler to split an input radio frequency signal into split radio frequency signals which are amplified by respective amplifiers and recombined in a second quadrature coupler in such a manner as to minimize intermodulation distortion products. A feedback loop is employed to assure that the split amplified radio frequency signals incident upon the second quadrature combiner are maintained in quadrature relationship to assure intermodulation product cancellation.

Abstract: A sample and hold phase detector for a phase locked loop includes a digital detector for detecting the frequency and phase difference between the reference signal and the voltage controlled oscillator (VCO) signal. In a first mode of operation, the digital detector generates a first signal relating the difference in frequency and in a second mode of operation generates a second signal relating the difference in phase. A capacitor stores the first or second signal depending on the operational mode of the digital detector. The capacitor is selectively discharged in response to a discharge signal produced by the digital detector when either the VCO frequency is higher than the reference frequency or following each detection of a phase difference. A first amplifier is used to bypass a portion of the loop filter to effect rapid changes in VCO frequency in the first mode while a second amplifier couples the control voltage to the VCO via the loop filter to maintain proper VCO frequency in the second mode.

Abstract: The invention is a high energy density electric cell having a lithium anode, and a copper oxide or cadmium oxide cathode. The electrolyte of the electric cell can be an organic solvent composed of propylene carbonate or nitromethane or a mixture of the two. The solute for the electrolyte is a soluble salt selected from the group of potassium hexafluorophosphate, lithium hexafluorophosphate and benzl trimethylammonium hexafluorophosphate.

Abstract: A knob assembly is provided which includes a knob having an integral shaft. The knob further includes a circular groove therein, and first and second cams situated in the groove. A knob receiving member includes an aperture in which the shaft of the knob is situated. Two snap fingers of flexible material extend from the sides of the aperture to engage the knob when the knob is pressed into the aperture. The knob is conveniently removed from the aperture by rotating the knob until the first and second cams contact and push the first and second snap fingers, respectively, out of the groove.

Abstract: An improved radiotelephone includes a unique microprocessor and peripheral devices for controlling the operation of portable or mobile radio transceivers in a cellular-type radiotelephone system. The microprocessor is coupled by a data interface unit and synchronization unit to the radio transceiver for transmitting and receiving Manchester-coded supervisory signalling having a 10 KHz bit rate. The microprocessor is also coupled by a unique self-clocking serial data bus and unique interface adapters to the radio transceiver for controlling the operating frequency, audio signals and transmitted RF signal thereof, to a keyboard for sampling the keys thereof, an off-hook switch and display for displaying telephone numbers, and to serial number and telephone number memories for accessing the stored serial and telephone numbers assigned to the radiotelephone.

Abstract: A unique method and apparatus for efficiently assigning duplex radio channels and scanning duplex radio channels assigned to mobile and portable radiotelephones in a cellular communications system is described. Each cell includes a base station radio having a signalling channel and a plurality of voice channels, and a base site controller adapted to utilize the methods embodying the present invention for controlling communications paths to mobile and portable radiotelephones. The base station radios include a signalling transceiver operable on the signalling channel, a plurality of voice transceivers each operable on a voice channel, and a scanning receiver for sampling the signal strength of active radiotelephones. Transmitters of signalling transceivers and voice transceivers are combined and coupled to an omnidirectional antenna; and the receivers of the signalling transceiver, voice transceivers and scanning receiver are couplable to one or more of six sector antennas.

Abstract: An improved encoder/decoder circuit which utilizes a phase locked loop frequency synthesizer configuration to permit both encoder and decoder operation. In addition, a sampling filter detector is employed to permit monolithic integration of the circuit and minimize sensitivity to vibration. The sampling filter detector has digitally controlled bandwidth which permits rapid response to reverse burst turn-off. In addition, the circuit includes a pulse adder to implement an energy limited reverse burst turn-off mode.

Abstract: An improved channel scanning radio which automatically monitors a channel being monitored by the scanning circuitry at the time of the microphone is taken off-hook by treating that channel as a priority channel for a short period after the microphone is returned to the hang-up position. This permits the operator to automatically monitor a channel of interest without stopping the scan function.

Abstract: In a frequency synthesizer phase locked loop including a reference oscillator, a variable reference divider (.div.M), a sample and hold phase detector, a loop filter, a voltage controlled oscillator and a variable divider (.div.N), a voltage converter for controlling the voltage of a control input to the voltage controlled oscillator is disclosed. In the preferred embodiment, the voltage converter has its input connected to the output of a first reference divider in the variable reference divider (.div.M) and its output connected to a control input (varactor diode) of the voltage controlled oscillator. The voltage converter clamps the divider reference signal from the first reference divider and provides a negative voltage level output to bias the varactor diode of the voltage controlled oscillator. Thus, the tuning range of the frequency synthesizer is increased.

Abstract: A television transmission system for asynchronously transmitting a television picture as a plurality of video samples over a narrow bandwidth medium from at least one remote transmitting site to a receiver at a base station. Improved synchronization between the transmitter and receiver are achieved by a dotting pattern consisting of alternating logic ones and zeros being sent by the transmitter to precede the video samples such that a sampling clock at the receiver synchronizes to the phase of the dotting pattern and thereafter samples the video signal. The video signals are also preceded by at least one predetermined digital word which identifies the particular remote transmitter and prepares the receiver to begin receiving the video samples. DC restoration circuitry determines the average value of the incoming video signals and to add an appropriate DC offset to the video signals to correct for any change in the gray scale of the video samples.

Abstract: Apparatus for processing received Loran C signals and compensating for envelope cycle discrepancy (ECD). A measure of ECD is determined during the fine settle operation and compared to a reference value which is an average over a period of time. If the difference between the reference and the ECD measure is greater than a threshold, the decision made by the fine settle operation is rejected and the fine settle process is restarted. If the difference is less than the predetermined threshold the decision is accepted as being an accurate fine settle determination.

Abstract: A data communications system is described that covers a geographic area divided into a plurality of non-overlapping zones and includes a general communications controller (GCC), a plurality of channel communications modules (CCM) and associated transmitters and receivers, and a plurality of portable radios. Message signals carrying alphanumeric information are communicated between the GCC and the portable radios by way of a radio channel. Each CCM takes a signal strength measurement every time it receives a message signal from a portable radio. The GCC gathers the signal strength measurements from the CCM receivers receiving the same message signal and computes an adjusted signal strength for each zone. The GCC then selects the zone having the largest adjusted signal strength for determining the location of the portable radio that transmitted the message signal.

Abstract: A frequency modulator for radio frequency (RF) signals is described that symmetrically modulates the RF signal with either binary signals or voice signals without distorting the amplitude of the binary signal near bit edges. The inventive frequency modulator includes a reference signal generator, a phase comparator for comparing the reference signal and a feedback signal to provide an error signal, a filter for filtering the error signal, a voltage-controlled oscillator (VCO) responsive to the filtered error signal for generating an output signal, a divider for dividing the VCO output signal by a predetermined number to provide the feedback signal, circuitry coupled to the VCO for modulating the VCO output signal with the binary signal, and circuitry coupled to the divider for varying the predetermined number of the divider between a first predetermined number and a second predetermined number in response to the binary signal.

Abstract: A trapped energy piezoelectric resonator for oscillator and multiple resonator applications has a piezoelectric substrate with electrodes disposed on each of its major surfaces. These electrodes are further comprised of a plurality of electrically interconnected and acoustically coupled sub-electrodes. The resonant frequency of these resonators may be controlled by varying the separation and, therefore, the acoustic coupling between the sub-electrodes. This resonator may be used in the feedback loop of an oscillator circuit as the frequency determining element. It may also be used to provide a resonator on a substrate carrying resonators of significantly different frequency.