Abstract: A control circuit and method of operating a battery charging system are provided capable of disabling charging of a rechargeable battery (320) based upon a second derivative (410) of a temperature of the battery. A thermistor (330), contained in a rechargeable battery pack together with the rechargeable battery (320), detects the temperature of the battery. Charging of the battery can be disabled when the second derivative (410) of the temperature of the battery is positive and the first derivative (390) of the temperature of the battery is higher than a predetermined threshold.

Abstract: Speech of an unknown amount and control message data (150) of known amount are multiplexed so that the coded voice data is transmitted before the elapse of a predetermined number of frames. A variable rate vocoder (110) receives and codes the speech of an unknown amount at one of full and less than full rates to produce the coded voice data. A multiplexer (120) receives the coded voice data from the variable rate vocoder (110) and sends frames containing the coded voice data when the variable rate vocoder operates at a full rate. When the variable rate vocoder (110) operates at a less than full rate, the multiplexer (120) sends frames containing portions of the message data together with the coded voice data.

Abstract: A switch circuit for a cellular radiotelephone operable in a TDMA communication scheme. The switch circuit is disposed upon a plurality of tandemly-positioned ceramic substrates having transmission lines disposed upon one of the ceramic substrates. The switch circuit alternately connects transmitter circuitry to an antenna or receiver circuitry to the antenna, thereby alternately to permit transmission or reception of signals generated by, or received by the radiotelephone. Because circuits disposed upon ceramic materials are of low insertion losses, the switch circuit is advantageously utilized to form a portion of the radiotelephone.

Abstract: The present invention provides an apparatus for symbol clock recovery from a received signal having wide range of frequency errors or offsets. Magnitudes of received inphase and quadrature sampled signals are determined (210). These magnitudes are summed and distributed (227) into accumulator registers (231, 232, 233, 235, 237, 239) for accumulating sums of the first and second signals for each sample time and substantially over a length of an expected burst. A maximum-minimum determination circuit (240) chooses the sample time having a largest or smallest sum to provide a recovered clock signal (270). The carrier could then be recovered (260), and a downsampler (250) downsamples the received inphase and quadrature signals based on the recovered clock signal.

Abstract: A filter duplexer, such as a filter duplexer for a radio transceiver, of minimum dimensions is disclosed. First and second filter portions of the duplexer each include a plurality of transmission lines. Cross sections of the plurality of transmission lines of each filter portion are of at least two different geometries. The amount of coupling between adjacent ones of the resonators, as well as the loading capacitances of such resonators, is controlled by the relative geometric configuration of the adjacent ones of the resonators. Because the amount of coupling between the resonators and the loading capacitances of the resonators is determinative of the filter characteristics of the filter duplexer, desired filter characteristics may be effectuated by careful selection of the geometric configurations of the resonators of each filter portion.

Abstract: A signal level indicator (204, 304) displays the magnitude of an input signal (421) by illuminating each of a number of five LEDs (314-318, 414-418) for an individual period of time. The number of LEDs to be illuminated and the individual period of time that each is to be illuminated varies with the magnitude of the input signal (421).

Abstract: A differential coherent modulation and demodulation method and apparatus non-coherently modulates (201) a data stream to generate non-coherently modulated data. The non-coherently modulated data is phase modulated (215) with a supplementary signal (211) to generate coded data. The coded data is then transmitted. A receiver (301) then receives the coded data. A non-coherent demodulator accepts the received coded data as input and demodulates the coded data to provide the original data and the supplementary signal (327).

Abstract: This invention relates to an interface for interfacing between two different types of networks, such as a GSM cellular radio network and an integrated services digital network (ISDN). The interface communicates between channels of one such network with channels of the other such network by mapping control information between the first (D) and second (Dm) control channels. In a first state of operation, the interface maps data between the first (B1, B2) and the second (Bm) data channels under the control of control information on the control channels. In a second state of operation, the interface maps data between the first control channel (D) and the second data channel (Bm) under the control of control information on the control channel.

Abstract: A diversity antenna structure and a diversity transceiver incorporating the same. Each antenna of the diversity antenna structure is formed of a first portion and a second portion. Second portions of each antenna are coupled to an electrical ground plane and form thereby ground plane portions of the respective antennas. Such second antenna portions are maintained in physical isolation from one another thereby, when receiving high frequency signals, to be maintained in apparent electrical isolation from one another. Because such ground plane portions are maintained in the apparent electrical isolation from one another, antennas of the diversity antenna structure may be positioned in close proximity to one another without causing coupling between the separate antennas of the diversity antenna structure.

Abstract: A telephone mounting receptacle (100) releasably affixes a portion of a cellular telephone thereto. Two facially opposed simultaneously retractable latch members (130, 140) engage with the portion of a cellular telephone when the retractable latch members (130, 140) are positioned in the latch position. An actuation force applied to either the right force receiving surface (162), or the left force receiving surface (163) of the mounting receptacle (100), simultaneously positions the retractable latch members (130, 140) into a release position. A spring-loaded element (170) applied against the bottom face of the telephone additionally works to "eject" the telephone. At this point, the telephone can be removed from the mounting receptacle (100).

Abstract: A hang-up cup for a telephone handset is provided having a hang-up cup housing (100) capable of accepting a portion of the telephone handset. A latch member (120) is hinged to the hang-up cup housing (100) by axial prongs (210) of the latch member (120) and curved prong (220) of the hang-up cup housing (100). A straight spring (230) is secured between spring retaining grooves (240) of the latch member (120) and wire support members (250) latch stops (270) are provided to restrict rotation of the latch member (120) about the hinge and prevents separation of the prongs (210, 220) upon excess rotation of the latch member (120) with respect to the hang-up cup housing (100).

Abstract: The present invention provides a downconverter method and apparatus for downconverting a multiphase modulated signal. The downconverter can be implemented in a multi-phase receiver such as a quadrature receiver. An analog-to-digital converter (103) converts an intermediate frequency signal to a digital signal at a sampling rate. A Hilbert transformation filter (104) and a delay element (105) connected in parallel provide respective passband quadrature and in-phase components of the digital signal. A digital translator (107) alters the passband quadrature and in-phase components based on a predetermined pattern to provide a baseband quadrature signal and a baseband in-phase signal. The digital translator (107) can be a pseudorandom sequence demodulator for demodulating a code division multiple access (CDMA) signal. Various types of DC estimation can also be provided in addition to automatic gain control.

Abstract: A support assembly, and associated method, for permitting a reduced-sized, card member to be received by a standard-sized, card reader assembly of a radio telephone. The support assembly is comprised of a frame formed of a standard-sized, card member having a through-hole extending therethrough. The through-hole is of dimensions corresponding to the card member of the reduced dimensions. A thin, support sheet covers a portion of an opening formed by the through-hole on a top surface of the frame to form a front joist thereby, and the thin, support sheet is folded about an edge of the frame similarly to form a rear joist over an opening formed upon a bottom face surface of the frame by the through-hole. The front joist and the rear joist together form a pocket for supporting the card member of the reduced dimensions within the through-hole.

Abstract: A dielectric filter having at least two adjacently-positioned resonators extended therethrough. The two adjacently-positioned resonators are of trapezoidal cross-sections to form thereby trapezoidal resonators. By suitable selection of the configurations of such resonators, the amount of coupling between such adjacent resonators may be controlled. For instance, a minor base side of the first trapezoidal resonator may be positioned adjacent to a corresponding minor base side of the adjacent trapezoidal resonator, or a major base side of the first trapezoidal resonator may be positioned adjacent to a major base side of the adjacent trapezoidal resonator, or a minor base side of the first trapezoidal resonator may be positioned adjacent to a major base side of the second trapezoidal resonator. Such electromagnetic coupling between the adjacent resonators is controlled by the relative configurations of such resonators rather than by increasing the spacings between such adjacent resonators.

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: The present patent application discusses a low profile information card chamber (107) used in a radiotelephone (101). The information card chamber accepts, retains and makes electrical contact to an information card (105). The information card chamber (107) makes electrical contact to the information card when the information card is properly inserted (105). The electrical contacts are located on the lower platform (213) of the information card chamber (107). Upon inserting the information card (105) into the information card chamber (107), the information card (105) is translated away from the electrical contacts (205). Prior to being fully inserted, the information card (105) is translated towards the electrical contacts (205). The two translational devices allow an information card (105) to be inserted into the information card chamber (107) without excessive wiping of the electrical contacts (205) by the information card (105).