Abstract: A detachable battery pack with a built-in broadband antenna is disclosed. Since the antenna is wholly contained within the battery housing, it is protected from damage and is detachable from the transceiver when the battery is detached. A transmission line structure formed between the battery and the transceiver is used to create an open circuit near the antenna feed point.

Abstract: A multipurpose hinge apparatus for a foldable telephone includes a flip element and a hookswitch. The flip element is held in the closed and open positions by an enclosed cam element which follows recesses in one shaft securing the hinge elements. The hookswitch is activated by another enclosed cam which follows a recess in a second shaft.

Abstract: A miniature shield with opposing cantilever spring fingers is disclosed. Shield walls, which may be part of a housing for electronic equipment, are designed to insert between a plurality of opposing cantilever spring fingers arranged in a "U"-shaped channel. Torque generated at the bottom of the "U"-shaped channel is minimized by the opposing cantilever spring fingers and enables the channel to be reflow soldered to an electronic circuit board.

Abstract: A frequency control apparatus and method is disclosed in which a frequency offset between a received signal and the local oscillator of a digital receiver is corrected in substantially one step.

Abstract: A continuously adaptive phase locked loop synthesizer is disclosed in which error correction pulses from a phase detector are separated into narrow pulse width and wide pulse width pulses. The wide pulse width pulses are coupled to the loop filter to enable a rapid charge of the loop filter to provide a VCO control voltage on a control line connected to the output of the loop filter. The narrow pulse width pulses are filtered by a narrow bandwidth filter before being applied to the loop filter thus enabling a slow charge of the loop filter. The narrow bandwidth filter is decoupled from the control line but referenced to the control line voltage.

Abstract: An antenna beam boundary detector for a sectorized cellular system is disclosed. The difference in signal level received by a main directional antenna and a broad beamwidth antenna is determined by detecting a modulator signal locally impressed on the signal received by the broad beamwidth antenna. The signal level difference factor is the directional antenna beam boundary when the two antennas are correlated. Interferometer effects are cancelled by detecting both amplitude and phase modulation of the locally impressed modulation.

Abstract: A surface mount dielectric block filter with an integral transmission line connection to external circuitry is disclosed. In order to connect an input/output capacitor metallized on the surface of the dielectric block to a substrate upon which the dielectric block is directly mounted, a transmission line of appropriate characteristic impedance disposed on the surface of the dielectric block is connected between one plate of the metallized capacitor and an input/output terminal. Two such dielectric block filters may be coupled together to form a radio transceiver duplexer.

Abstract: An internally mounted broadband antenna utilizing two resonators and a reactive ground feed is disclosed. A nonconductive notch separates a conductive surface into two portions which are coupled to a respective one of each resonator. Each resonator is a microstrip conductor forming a transmission line with its respective conductive surface portion. Coupling to the antenna is accomplished by connection across the notch.

Abstract: A cellular radiotelephone system is disclosed in which the signalling protocol for the system is embedded in the frame synchronization of the digital messages transmitted on the system. Multiple functions are accomplished by the synchronization signal and include call supervision, mode definition, and data frame synchronization. The synchronization signal is a high auto correlation, low cross correlation sequence of a predetermined number of data bits. Different bit sequences may be employed as a synchronization signal while conveying call supervision information defining the serving fixed site. Additionally, the logical inverse of the synchronizing signal may be utilized interchangably with the synchronizing signal to define the fixed site. A repetitive pattern of synchronizing signals and logical inverse synchronizing signals convey system mode information without increasing signalling overhead or losing the correlation performance of the full synchronization word.

Abstract: A time division multiple access (TDMA) radio system conveying a quadrature phase shift keying (QPSK) modulated data signal is disclosed. In order to overcome multipath distortion and phase variation introduced by the radio channel, a synchronizing poriton of a TDMA timeslot is transmitted in only one vector of the QPSK modulation. The system utilizes the one vector synchronizing portion to develop a channel profile estimate which is applied to the received message portion of the QPSK data signal to compensate for the multipath distortion and phase variation during one TDMA timeslot.

Abstract: A digital radiotelephone exchange having self diagnostic individual subchannel loopback is disclosed. An individual subchannel of an outbound PCM data stream is substituted for an individual subchannel of an inbound PCM data stream. The removed individual subchannel of the inbound PCM data stream is either substituted in the outbound PCM data stream or discarded. Line signal bits may be generated and substituted for the line signal bits of the individual subchannel in the outbound PCM data stream.

Abstract: A mobile radiotelephone call synchronization method and apparatus for a radiotelephone system utilizing a credit card for payment of calls is disclosed. Call access is denied a mobile unit until the user runs his credit card through a card reader to input credit card information. After checking list having a valid and invalid I.D., and checking the expiration date stored at the mobile telephone, the information is communicated by the mobile unit to a registration computer for approval. If approval is granted, the mobile unit is enabled for the user to make one or more radiotelephone calls.

Abstract: The method and apparatus for rapid phase acquisition and random radio channel phase error compensation for a TDMA QPSK receiver is disclosed. Received quadrature signals having a known synchronizing sequence transmitted on one of the vectors is correlated to a local replica of the sequence. The output correlation detection signals are held for the duration of the TDMA timeslot and multiplied by the received quadrature signals to produce two pairs of products. The mutually exclusive product pairs are summed to recover data having the random phase error compensated.

Abstract: A portable radiotelephone with control switch disabling is disclosed. A flip element which contains a microphone and covers a keypad and other control buttons when in a closed position also activates a hookswitch. When the hookswitch and microprocessor indicate that the flip element is in a closed position, the on/off switch cannot be activated to turn the portable radiotelephone on or off and switches which control volume level are deactivated.

Abstract: The method of conveying control and program information between cellular radiotelephone controllers and of detecting information errors is disclosed. When a program memory information error is detected, a predetermined amount of memory information is conveyed from a first controller to a second controller. If a comparison of checksums of a predetermined amount of memory information stored at the second controller and the memory information received from the first controller matches, additional memory information is conveyed. If a match is not found, the predetermined amount of memory information is reconveyed from the first controller to the second controller.