Abstract: Method and apparatus for communicating credit card information read at a mobile radiotelephone unit is disclosed. Data read from a credit card is placed in a variable length error protected format and transmitted from the mobile radiotelephone unit to authorize payment of the radiotelephone call.

Abstract: A multiresonator dielectric block filter is disclosed in which capacitive coupling between resonators disposed in the dielectric block is controlled by an electrode strip coupled to the conductive material covering the majority of the dielectric block surface. The electrode strip extends at least partially between two adjacent resonators to control the capacitive coupling between the resonators.

Abstract: A method and apparatus for phase-coherently demodulating a multipath-impaired time division multiple access QPSK data timeslot is disclosed. A quadrature separator generates multipath-impaired intermediate signals which, during a predetermined synchronizing sequence for the timeslot, are applied to a pair of synchronizing correlators to generate quadrature multipath profiles. These profiles then are used to modify subsequently received QPSK timeslot signals at the separator outputs to coherently construct multipath compensated I and Q channel data.

Abstract: An analog frequency inversion scrambler employing an exchange of random number seeds between an originating scrambler and an answering scrambler to create two pseudo-random frequency hopping rolling codes has been disclosed. The rolling code used in one direction of a duplex channel is different than the rolling code in the opposite direction and each code is synchronized by periodic synchronization signals.

Abstract: The apparatus and method for transferring radio specific data from the memory of an integral logic unit of a radiotelephone to a second, replacement, memory is disclosed. Security of the data is realized by encoding the radio specific data with an operative number generated from a seed number. If the radio specific data is properly transferred to the second memory, the radio specific data is deleted from the memory of the integral logic unit.

Abstract: A cellular system employing time division messages transmitted from a plurality of radiators in each cell is disclosed. A first electromagnetic signal at a particular frequency is transmitted during one time slot from one of the plurality of radiators. A second electromagnetic signal at the same frequency is transmitted during another time slot from a second one of the plurality of radiators. A remote unit selects the best electromagnetic signal and communicates the selection to a cell controller, which selects a third time slot for transmission of a message from the radiator transmitting the best electromagnetic signal.

Abstract: An improved leadform for use with surface mount components is described. The improved leadform provides a connection to a printed circuit substrate which is highly resistant to stress related failures. The leadform is configured so that the connection utilizes a relatively greater area of the leadform for contact with a solder connection resulting in a more compliant connection. In addition, the present invention provides a preparation for the printed circuit media which allows the substrate media to absorb stresses which occur due to thermal cycling.

Abstract: A coaxial data bus distribution apparatus for coupling a variable number of peripheral devices to the data bus with a predetermined electrical distance between each point of coupling. A coaxial cable of predetermined length is connected between the output connector of a first input-output pair of coaxial connectors and the input of a second pair of coaxial connectors. Connection between the coaxial connector pair, mounted on a bus interconnect board, and a peripheral device is made by a predetermined length two wire non-coaxial connection to a peripheral device back plane.

Abstract: A microstrip resonator (311) for a circulator/isolator is disclosed employing radial (815, 817, and 819) and circumferential (821, 823, and 825) slots to load the resonator and reduce the frequency of resonance. A resonator of small physical size is thus formed having a discontinuous outer ring (segments 807, 809, and 811) and a central triangle portion (827) each electromagnetically coupled to a ferrite element.

Abstract: A cellular radiotelephone system providing service to remote units having a voice operated transmitter (VOX) is disclosed. If the regularly scheduled periodic signal quality measurements made by fixed site equipment indicate that the remote unit signal has not been received for a predetermined number of measurements, an audit request is transmitted to the remote unit. The remote unit responsively keys its transmitter for a predetermined period of time. A first special scan is programmed into the regular process such that the fixed site equipment may continue with its regular process until the signal quality measurement must be made. A second measurement is made following the first and if the two signal quality measurements made while the VOX remote unit is known to be transmitting agree, system reconfiguration for the service of this remote unit may be implemented by the cellular system.

Abstract: The method and apparatus for interfacing between a cell site controller, a cell system controller, and the radio transceivers of a cellular radiotelephone system is disclosed. To convey control information to the radio transceivers, the cell site controller enables one of a redundant pair of control data buses to a selected transceiver by placing an enable signal on the enable line unique to the selected transceiver. Control data is then coupled to the common enabled control data bus for conveyance to the selected transceiver. The transceiver mutes the message data port it may be using and transponds the control data information it receives. When the enable signal is removed, the transceiver unmutes the message data port. Program information is transferred between the cell system controller and cell site controllers as memory blocks which may be retransferred upon detection of a checksum mismatch.

Abstract: A shortened wideband decoupled sleeve dipole antenna is disclosed in which a helically wound upper radiating element and an inductively loaded lower radiating sleeve element reduce the linear size of the antenna. Substantial decoupling is provided by a helically wound feed coaxial transmission line within the sleeve element. A matching network at the antenna feed point provides capacitive reactance above the antenna resonant frequency and inductive reactance below the antenna resonant frequency such that an impedance match between the feed coaxial transmission line is obtained at frequencies above and below the resonant frequency and dual-band performance may be obtained.

Abstract: A method and apparatus for utilizing voice channel transceivers as temporary scanning receivers in a handoff event for a cellular radiotelephone system is disclosed. Voice channel transceiver identifications are stored in link lists according to priority, sectorization, and last use. When a signal strength measurement is required, those cell sectors having available voice channel transceivers are identified and a table providing optimum transceiver selection is utilized to select those voice channel transceivers which will make the signal strength measurement.

Abstract: A high efficiency RF power amplifier is disclosed in which a field effect transistor is operated in a class F mode. A third harmonic quarterwave open circuit transmission line stub having a Z.sub.O adjusted to provide capacitance series resonant with transistor inductance at the second harmonic is coupled to the transistor output lead to produce a low impedance at the channel drain of the transistor. Parallel resonance of the transistor die capacitance and interconnect inductance coupled to ground by the transmission line produces a third harmonic high impedance at the channel drain. Further lowpass output matching circuitry provides a constantly increasing impedance magnitude from the transistor die to the load and provides load mismatch isolation to the second and third harmonic impedances at the channel drain.

Abstract: A dielectric block filter which may be mounted on a printed circuit board or other substrate as a single component is disclosed. The dielectric filter utilizes metalized hole resonators having coupling characteristics determined by the metalization pattern on one surface of the dielectric block. Input and output coupling is accomplished via terminals asymmetrically arranged in a mounting bracket. Mounting tabs on the bracket opposite a recessed area holding the dielectric block secure the filter to the circuit board and provide ground connection for the filter.