Abstract: A medium access protocol which adjusts number of contention slots in a variable length frame and superimposes a variable window structure over the frame structure. The number of contention slots (24) in a frame (28, 30) is changed on a frame by frame basis by determining if a collision occurred in any contention slot (44). If not the contention slot is removed (48) and if so, the number of slots is increased (52). In high traffic situations, if the average load is greater than a threshold (107, 120) the number of frames in a window is increased (130). If the load drops below the threshold (120), the number of frames per window is decreased (124).

Abstract: A PIN diode antenna RF switch especially suited for a multi-mode transceiver that includes a full duplex mode such as an AMPS analog mobile telephone. Six PIN diodes (30, 32, 34, 36, 42, 46) are configured as RF switches which are controlled by an arrangement of four DC switches (60,64,68,72) to produce a high degree of isolation in a path parallel to a duplexer (52) and low insertion loss in transmitting modes while optimizing current drain.

Abstract: A buck or boost (BOB) power converter circuit. A buck converter is cascaded with a boost converter to form a buck or boost circuit (20). The BOB converter is controlled by a controller (26) such that only the buck or boost converter is operating at any given time. A reference signal Vref can be applied to the controller (26) such that the output voltage from the converter closely tracks the reference signal. Positive and negative ramp signals are generated and an error feedback signal is compared with the ramp signals to control the output in accord with Vref. This is useful in application of the output voltage as the power supply to an RF Power Amplifier (16) so that the reference signal can represent the envelope of a signal to be transmitted and the RF PA (16) can operate at high efficiency.

Abstract: A battery charging method (300) determines a current at which to start charging the battery which provides the capability for faster higher current sourcing capability. A start current(Istart)is determined based on the battery's cut off voltage, steady state voltage, and characteristic impedance (314). This start current is then compared and adjusted based on the rated power supply current for the power supply (316, 318) and rated charge current for the battery (320, 322). The adjusted current is then applied to the battery (324) at the beginning of the charge sequence to provide faster higher current sourcing capability.

Abstract: An antenna feedpoint assembly includes a printed circuit board (400), a signal conductor feed element (2041) mounted on the printed circuit board (400), and a secondary ground element (106) placed parallel to the signal conductor feed element (2041) wherein an electromagnetic coupling is made between the signal conductor feed element (2041) and the secondary ground element (106) for an improved matching of the antenna (100) without an additional matching circuit. The secondary ground element (106) comprises a mounting portion (1061) connected to a ground plane (1002) and a protruded portion (1062) extended from the mounting portion (1061) such that the protruded portion (1062) is elevated from and substantially parallel to the signal conductor feed element (2041) serving as the antenna feedpoint contact.

Abstract: A multimode fast attack automatic gain control (AGC) circuit (100) includes an analog feedback loop and a digital feedback loop. The analog feedback loop is switched into the amplifier stage (102) by a first switch (126) when dynamic control of the gain attenuation is desired. The digital feedback loop is switched into the amplifier stage when attenuation is to be adjusted periodically, such as between sequentially received time slots in a time division multiple access (TDMA) mode of communication.

Abstract: An antenna assembly (100) includes an antenna (114), antenna mounting base (108), and a radio housing (102). The antenna mounting base (108) includes a through-hole (112) and a snap beam (116). The antenna (114) is inserted into the mounting base (108) via the through-hole (112), and the mounting base snap fits into the radio housing (102) via the snap beam (116). The snap beam (116) operates as both a snap-fit feature for retaining the antenna mounting base within the housing ((102) and as a release mechanism for removing the antenna mounting base from the housing.

Abstract: A detector circuit (1) includes a coupler (2) having a primary port (10) and a reflector port (11). The primary port (10) has an input node for receiving radio frequency signals from an amplifier (7) and an output node coupled to an antenna port (ANT). There is a rectification circuit (3) having an input coupled to the reflector port (2) and a low pass filter (4) is coupled to an output of the rectification circuit (3). The detector circuit also includes a comparator (5) having a reference input (Vref) and a signal input (Vin). The reference input (Vref) is set to a voltage threshold level and the signal input is coupled to an output of the low pass filter (4). In use signals at an output of the comparator (5) are indicative of a missing or mismatched antenna coupled to the antenna port (ANT).

Abstract: A planar electromagnetic device, such as a planar transformer or planar inductor, is provided with features for cooling that are formed integrally with the windings of the planar device. In a preferred embodiment the planar device uses winding layers (200) having fin portions (116). In a first alternative embodiment a helical winding (500) is formed from a winding stamping (400) having fin portions (412). In a second alternative embodiment, tube portions (802) are formed in a winding stamping (700) used to form a helical winding.

Abstract: A phase lock loop (100) includes a dual-state charge pump (120) having a first current source (220), a second current source (230) coupled in series to the first current source, a third current source (240), a fourth current source (250) coupled in series to the third current source, and control circuitry (210) coupled to the first, second, third, and fourth current sources. The charge pump can be programmed to be in an adapt mode with large up and down currents or in a normal mode with small up and down currents. The duration of the adapt mode can be programmed by a timer. The phase lock loop has a wide loop bandwidth and a faster lock time during the adapt mode and a narrow loop bandwidth and less phase noise during the normal mode.

Abstract: A mobile communication device (102) communicates over a wireless bearer network which includes a base station (104) and a wireless communication system (108). To provision wireless application services the mobile communication device contacts a provisioning proxy (110) over the wireless bearer network, which in turns contacts a provisioning center (116) over a public network (114). A provisioning tunnel is then established between the provisioning center and the mobile communication device. Once the provisioning tunnel is set up, the user of the mobile communication device can subscribe to, or unsubscribe from wireless application services.

Abstract: In one embodiment of the invention, an antenna (104) includes an antenna cavity used for receiving a removable stylus (108). A retention feature such as a snap (112) helps retain the stylus (108) to the antenna (104) when not in use. In an alternate embodiment, the stylus (504) is an inlay to the outer wall of antenna (506). In still another embodiment of the invention, a removable antenna stylus (300) serves as an antenna when attached to radio (404) and as a stylus when removed from the radio (404).

Abstract: A communication session is established between a client (102) and a server (104) over a first bearer network (106). A session identifier is produced (304), which is compressed (306). Messages or packets sent between the client and server during a first connection include the compressed session identifier and a first envelope identifier. At some time the first connection is terminated, and a second connection is initiated on a second bearer network. At the occurrence of the break, at both the client and server, a session transition control block is set up and includes the first envelope identifier. The session transition control block is used to map messages or packets received after the break to the correct session after resuming the session over a second connection with a second envelope identifier.

Abstract: A power amplifier includes a carrier amplifier path and a peaking amplifier path. The carrier amplifier path includes a carrier amplifier (208), and an impedance transforming network (214). The peaking amplifier path includes a peaking amplifier (210), an impedance transforming network (216), and a phase delay quarter wave element (226). The arrangement forms an inverted Doherty combiner where as the nominal impedance at a summing node (230) increases with increased conduction from the peaking amplifier, the load impedance at the output of the carrier amplifier decreases so as to maintain the carrier amplifier at a saturation point as the input signal (232) increases, and results in a reduction of the number of phase delay elements needed over a conventional Doherty approach. In a preferred embodiment the carrier and peaking amplifiers consist of cascaded stages, and are disposed on a common integrated circuit die (304).

Abstract: An antenna system includes a main antenna (16) and a parasitic element (18). The parasitic element (18) is rotatably coupled (24) to the main antenna (16), the antenna system being movable from a closed position to an open position, in which the main antenna (16) is coupled to the parasitic element (18) to cause the parasitic element (18) to operate as a passive radiator element and to radiate (32) along with the main antenna (34) to enhance the gain of the antenna system.

Abstract: A crystal reference (100) comprises a crystal element (102) integrally housed with a memory device (108), and is coupled to the memory device through an anti-resonant network (110). The network is designed such that it presents a high impedance at the natural frequency of the crystal element. Temperature performance information for the particular crystal element is stored in the memory device, and is accessed via terminal (112) using a single wire interface protocol.

Abstract: A communications system for providing packet data service to mobile stations (110) performs registration of the mobile station prior to engaging in packet data service. The registration procedure includes sending a request to register (300) to a DAP (113), transferring (302) subscriber data from a HLR (124) to a D-VLR (126), authenticating (306) the mobile subscriber, selecting a mobile data gateway (116) to service the mobile station, transferring (308) the subscriber data from the D-VLR to the mobile data gateway, and establishing (312) a packet data link between the mobile data gateway and the mobile station.

Abstract: A portable communication device (104), such as a cellular telephone, is operable in a speakerphone mode. The communication device uses a digital communication scheme, and both receives and generates vocoded signals. The speakerphone provides half duplex operation to eliminate echo. When voice activity is detected, the device activates a speaker and mutes a microphone to avoid echo. When no voice activity is detected in the received signal, the speaker is muted and the microphone activated. To determine when speech activity is present in the received signal, a novel voice activity detection (VAD) algorithm is used which takes advantage of parameters provided as part of the received vocoded signal. The new voice activity algorithm includes calculating a staggered average of the frame energy value for a sequence of received frames, and determining if the staggered average value exceeds a threshold.

Abstract: The invention produces an accurate quadrature relationship for a range of frequencies using passive components in the primary quadrature splitting circuits. A reference oscillator (202) generates a reference signal which is fed to a conventional passive quadrature splitter circuit (204). However, since the reference circuit provides signals over a range of frequencies, the output signals of the passive quadrature splitter may not have an accurate quadrature relationship. The output signals of the passive quadrature splitter are then equalized in magnitude, and the sum and difference of the signals are produced, which will be in an accurate quadrature relationship.