Abstract: A switch for a card reader assembly forming a portion of a radio transceiver. The switch is operative responsive to positioning of a card member at a support position of the card reader assembly. The switch is operative to move out of a first switch position and into a second switch position responsive to actuation forces exerted upon the switch by the card member. The actuation forces are exerted by the card member to position the switch at the second switch position only when the card member is positioned at the support position. A lever arm of the switch includes a force receiving surface for receiving actuation forces generated by the card member when positioned thereagainst. Application of the actuation forces generates twisting moments to cause pivotal movement of the lever arm about a pivot arm.

Abstract: A frequency control circuit, and associated method, for a receiver operative to receive a TDMA signal transmitted by a transmitter in a TDMA communication system. A first frequency detector generates a first frequency control signal. A second frequency detector, comprised of a portion of a decision-directed demodulator, generates a second frequency control signal. The first frequency control signal is utilized to effectuate frequency control when a signal is continuously received by the receiver, such as times immediately subsequent to initial powering of the receiver as the receiver becomes synchronized with the TDMA signal transmitted thereto. Onces a receiver becomes synchronized to the transmitter, the receiver need only be powered during intermittent time periods when the TDMA signal is transmitted to the receiver.

Abstract: A filter assembly comprised of a dielectric filter and a shield positioned about the dielectric filter. The dielectric filter may be surface-mounted upon a circuit board and includes at least one notch formed to extend along a side face surface thereof. The shield is integrally formed of two sheets of an electromagnetic wave-absorptive material interconnected by a shoulder forming a right angle to fit about two sides of the dielectric filter. At least one projecting prong, corresponding in number and position with the at least one notch of the dielectric filter, extends beyond an end surface of one of the sheets of the shield to interfittingly engage with a corresponding notch formed on the filter. The shield is positioned about the dielectric filter prior to tuning of the filter, and openings are formed to extend through the shield to permit access to the dielectric filter to permit tuning thereof once the shield is positioned thereabout.

Abstract: A fastener for a housing assembly. The fastener is comprised of a key having a hooked end portion formed to project beneath a front housing assembly portion, and a track member formed in a side wall of a rear housing assembly portion. Top and bottom face surfaces of the hooked projecting portion of the key, and top and bottom ledge surfaces of the track member are semi-circular in configuration. Interfitting surfaces of the front and rear housing assembly portions are also semi-circular in configuration. When the front and rear housing assembly portions are tandemly-positioned, and aligned with one another, the hooked end portion of the key and the track member engage with one another. Radial translation of the front housing assembly portion repositions the key projecting therebeneath at a fastening side of the track number to fasten thereby the front and rear housing assembly portions theretogether.

Abstract: A phase-locked-loop circuit for a radio transceiver operative to transmit and to receive modulated signals during nonconcurrent time periods. During time periods in which the radio transceiver is to generate and to transmit a modulated signal, the phase-locked-loop circuit is connected to the transmitter portion of the transceiver. During time periods in which the radio transceiver is to receive a modulated signal, the phase-locked-loop circuit is connected to the receiver portion of the transceiver. A switch, preferably comprised of a multiplexer, alternately connects the phase-locked-loop with the transmitter portion and the receiver portion of the transceiver.

Abstract: A Viterbi equalizer for decoding a .pi./4 DQPSK modulated signal. Because symbol values of adjacent symbols of a .pi./4 DQPSK signal are offset in phase relative to one another, allowable values of succeeding states of a .pi./4 DQPSK signal are four in number. The signal paths of the Viterbi equalizer are thereby limited in number to four allowable next-states, and the Viterbi equalizer is operative to select certain ones of the paths connecting the states at the adjacent time intervals as survivor paths to form maximum likelihood paths thereby.

Abstract: A battery charger assembly for applying a charging current to a rechargeable battery pack having at least one battery cell. Charging circuitry is supported within a housing body and includes coupling electrodes which protrude beyond a front side wall surface of such housing body. Gripper arms are hingedly-connected to the housing body to protrude beyond the front side wall of the housing body. The battery pack to be recharged is positioned between the gripper arms which generate a gripping force upon opposing sides of the battery pack to maintain the battery pack at a charging position whereat the charging current is applied to the battery cells of the battery pack.

Abstract: A system, and associated method, for measuring a signal level of a signal received by a receiver, such as a radio telephone. The signal received by the receiver is applied to a variable amplifier. The amplification of the variable amplifier is adjusted such that an amplified signal generated therefrom is within the dynamic range of an intermediate frequency circuit. The level of amplification required to position the signal level of the amplified signal within the dynamic range of the intermediate frequency circuit is measured, and the signal level of the signal received by a receiver is calculated.

Abstract: A carrier assembly for an electronic device, such as a radiotelephone. The carrier assembly is comprised of a frame and a support arm pivotally coupled thereto. The frame receives the electronic device to engage supportively the electronic device thereat, and latch members latch the electronic device to the frame. The support arm is pivotally coupled to the frame to permit positioning of the support arm to form either a clip or a table-support. When positioned to form a clip, the carrier assembly permits carriage of the electronic device by way of supportive engagement of the device to an external object, such as a belt or other article of clothing, of a user. When positioned at the table-support position, the support arm is operative to support the electronic device in a desired orientation upon a surface.

Abstract: A filter duplexer, such as a filter duplexer for a radio transceiver, of minimum dimensions is disclosed. A first filter portion of the duplexer filter includes resonators of a first geometric configuration, and a second filter circuit portion of the duplexer filter comprises resonators of a second geometric configuration. The geometric configuration of the two filter circuit portions are dissimilar such that relative characteristic admittances of the resonators of the respective filter circuit portions are dissimilar. Because the resonators of the two filter circuit portions are of dissimilar electrical characteristics, a desired frequency response of the duplexer filter may be obtained with similar resonator loading capacitances.

Abstract: A radiotelephone system comprised of a radiotelephone-pair suitably intercoupled theretogether to permit transfer of data, such as NAM information, therebetween. A first of the radiotelephone-pair comprises a radiotelephone of conventional construction. A second radiotelephone of the radiotelephone-pair comprises a radiotelephone having circuitry to transmit efficiently an information signal upon a cellular, communication system of increased capacity. The data sequence contained in the first radiotelephone is transferred to the second radiotelephone to permit a communication link to be formed between the second radiotelephone and a cellular, communication network.

Abstract: A telephonic handset housing assembly for a cordless telephone. The housing assembly comprises a carriage and a clip which is releasably engageable with the carriage. Because the clip is releasably engageable with the carriage, when the handset is not to be carried with an object, the clip may be removed so as not to form a portion of the handset housing assembly.

Abstract: A fastener for fastening front and rear housing portions of a housing assembly theretogether. A resilient tongue member is affixed to a surface of the rear housing portion to extend upwardly therefrom. A beveled, top edge surface of the resilient tongue member defines a ramped, face surface which extends to a back-angled, force-receiving surface. A hook member positioned beneath the front housing portion is positioned to permit mated engagement with the tongue member. The hook member is permitted elastic deformation responsive to application of forces thereupon by the ramped, face surface of the resilient tongue member during translation of the hook and tongue members into a fastening position. Once positioned in a fastening position, the hook member returns to a nondeformed state, to fasten the tongue member in position thereat, thereby to fasten the front and rear housing portions theretogether.

Abstract: A gain control circuit for a radio transmitter, such as the radio transmitter portion of a radiotelephone operative to transmit a .pi./4 DQPSK-modulated signal in discrete bursts. The signal portion of the signal transmitted during each discrete burst forms a slot and at least one of the slots includes a pre-determined data sequence portion. The peak power level of the portion of the slot comprising the pre-determined data sequence portion, once amplified by amplifier circuitry of the radiotelephone, is compared with a stored value representative of the peak power level of a corresponding portion of a slot amplified to be of a desired signal level. Responsive to such comparison, the amplification level of the amplifier circuitry is altered.

Abstract: A system and method for correcting for Rayleigh interference of a signal transmitted upon a multi-path channel. The system adaptively calculates values of channel gain and noise variance of the channel upon which the signal is transmitted, and generates signals indicative of such calculations which are supplied to a decoder. The system may be utilized to form a portion of a coherent, or noncoherent receiver which receives encoded and differentially-encoded signals.

Abstract: An assembly, and associated method for constructing such, for connecting an electrical circuit to an electrical cable, such as an antenna connector pin, or, alternately, to a coaxial transmission line. An antenna circuit board includes a circular aperture extending therethrough for receiving a socket member to be supported thereat. Angled, segmental-slots are formed about the circular aperture and receive projecting prong-members of a clip member. The socket member receives the electrical cable, such as the antenna connector pin, or a coaxial conductor pin therein. The clip member engages with a coaxial tube of the coaxial transmission line. The assembly permits alternate connection thereto of either the electrical cable or the coaxial transmission line thereat.

Abstract: A dielectric filter construction having at least two resonating cavities extending longitudinally through a block of dielectric material. At least one of the resonating cavities is of a cross-sectional area which is elongated in a transverse direction, and at least one notch is formed to extend longitudinally along at least one of the surfaces of the block of dielectric material between adjacent ones of the resonating cavities. By appropriate selection of the amount of elongation of the cross-section of the resonating cavity, and the location and dimension of the notch formed along the surface of the block, the component values of the component elements comprising the filter may be selected over an increased range without altering the physical size of the filter.

Abstract: An electrically-conductive, elastomeric connector for electrically connecting a circuit path of an electrical circuit disposed upon a substrate having an electrically-conductive edge portion which forms a portion of the electrical circuit with an electrically-conductive cover which covers at least a portion of the substrate. The elastomeric connector comprises a tubular-shaped body elongated along a longitudinal axis thereof, and a central aperture extending through the tubular-shaped body. Compressive forces exerted against the tubular-shaped body when positioned against the electrically-conductive cover causes seating of the tubular-shaped body against the electrically-conductive cover. First and second claw arms extend beyond a side surface positioned in opposition to the seating surface of the tubular-shaped body. The claw arms permit affixation of the tubular-shaped body to an edge portion of the substrate.

Abstract: A system, and associated method, for measuring a signal level of a signal received by a receiver, such as a radio telephone. The signal received by the receiver is applied to a variable amplifier. The amplification of the variable amplifier is adjusted such that an amplified signal generated therefrom is within the dynamic range of an intermediate frequency circuit. The level of amplification required to position the signal level of the amplified signal within the dynamic range of the intermediate frequency circuit is measured, and the signal level of the signal received by a receiver is calculated.

Abstract: A support assembly for a transportable radiotelephone. The support assembly forms a transceiver unit receiving platform which supportively affixes a transceiver unit in position thereat when positioned thereat. Connection with a battery supply, a handset, and an antenna is formed by merely properly positioning the transceiver unit at the transceiver unit receiving platform.