Abstract: A dual-band cellular telephone antenna. A monopole antenna is tuned to a first resonant frequency of operation. A first helical antenna is coupled to the monopole antenna and has turns surrounding the monopole antenna, where the first helical antenna is tuned to a second resonant frequency of operation. A grounded second helical antenna surrounds the first helical antenna and is formed to have an upper capacitive loading segment to tune the grounded second helical antenna at substantially the second resonant frequency of operation. The cellular telephone has a housing formed of a conductive material. A printed circuit board (PCB) has a metalized ground plane, wherein the metalized ground plane and the grounded second helical antenna are coupled to the cellular telephone housing.

Abstract: A method for receiving a radio communication in a radio communication system (100) shares the downlink processing burden among members of a local group of local stations. The method includes receiving the radio communication (302) at a first mobile station (304) of a plurality of mobile stations (300). The method further includes transmitting a local radio communication (306) from the first mobile station to an intended recipient mobile station (308) of the plurality of mobile stations.

Abstract: A wireless communications device (100), after determining it can not locally satisfy a request for network data (201), sends a search query or request for data to a proximal device that has a network cache function (202). The proximal device searches for the requested data (203) and if the data is found, then the data is sent to the requesting wireless communications device from the proximal device (206). The data request is sent over a wide area network (204), for example, the Internet, if the proximal device does not have the requested data stored in a memory on the proximal device (204). The wireless communications device stores the data for subsequent use and, if necessary, subsequent provision to a proximal device.

Abstract: A searcher receiver (114) includes a sample buffer (202) which stores signal samples loaded using a real time clock. A real time linear sequence generator (RT LSG) (206) stores an initial state and is clocked using the real time clock. The contents of the RT LSG are loaded into a non-real time linear sequence generator (NRT LSG) (208) when sample processing begins. Samples are correlated using a non-real time clock to allow signal processing to be uncoupled from the chip rate. The analog front end (108) may be powered down or tuned to another frequency during non-real time processing.

Abstract: A method of and apparatus for optimizing a minimum turn around time (MTAT) between (a) a reception by a first device of a first infrared data communication (IRDC) frame sent from a second device and (b) a transmission by the first device of a second IRDC frame to the second device. The MTAT value received from the second device is loaded into a storage device. The first IRDC frame from the second device is received, and a counter of the first device either resets upon reception of each of the plurality of characters of the first IRDC frame or increments when none of the plurality of characters are received. The first device transmits the second IRDC frame to the second device when the counter value reaches the MTAT value.

Abstract: A latching assembly for a battery door of a portable electronic device includes a latch body that is retained on either the battery door or the housing of the device and which includes an encapsulated biasing spring and snapping catches that cannot be accessed by a user.

Abstract: The apparatus and method of the present invention provides a system for spanning operation of a mobile station (110) between a public cellular system (100) for packet data service and a private autonomous cellular system (102) for circuit services when both services are available. In the disclosed system, the mobile station (110) remains on the public system (100) until a circuit call needs to be set up. If the mobile station (110) receives a call on the autonomous system (102), it is notified by the public system (100) via a tunneling message. If the mobile station (110) wishes to originate a call, it switches to the control channels of the autonomous system (102). If the signal strength of the autonomous system (102) falls below a predefined threshold, the mobile station (110) exits the disclosed dual mode, thereby receiving both packet and circuit services from the public system 100.

Abstract: A power amplifier load adjust system includes a power amplifier and a variable impedance network coupled to the output of the power amplifier. The variable impedance network presents a plurality of impedances to the output of the power amplifier responsive to a load control signal. A control circuit generates a transmit power command and a channel frequency command. Memory stores a plurality of control values as a function of output power and frequency. A processing circuit coupled to the variable impedance network, the control circuit, and the memory retrieves the plurality of control values and uses them to generate the load control signal in response to the transmit power command and the channel frequency command.

Abstract: A method for receiving a radio communication in a radio communication system (100) shares the downlink processing burden among members of a local group of local stations when receiving an alert communication such as a paging channel. The method includes receiving the alert communication (302) at a first mobile station (304) of a plurality of mobile stations (300). The method further includes transmitting a local radio communication (306) from the first mobile station to an intended recipient mobile station (308) of the plurality of mobile stations.

Abstract: A cradle for a wireless device such as a cellular telephone. The cradle provides a second antenna for antenna diversity operation of the wireless device. Optionally, the cradle contains any of hardware circuitry, processing, and software to provide antenna diversity operation in conjunction with the wireless device.

Abstract: A code division multiple access (CDMA) cellular telephone with reduced transmissions from the CDMA cellular telephone to a remote base station. A variable rate vocoder is operable to receive an input signal and encode the input signal at any of a plurality of frame rates responsive to an amount of audio content present in the input signal. A controller monitors an encoding rate of operation of the variable rate vocoder and detects when the variable rate vocoder operates at a predetermined rate. The controller then causes a transmitter coupled to the variable rate vocoder to reduces a duty cycle of operation.

Abstract: A variable gain element for adjusting a magnitude of an input signal. The variable gain element includes a first differential transistor pair having a first transistor coupled to a second transistor. A second differential transistor pair couples the second transistor to a supply voltage and to an output terminal of the first transistor. A load resistor couples the output terminal to the supply voltage. A control voltage applied to an input of the second differential pair causes a varying amount of current cancellation through the load resistor.

Abstract: A cellular telephone holster includes a holster section formed to accept a cellular telephone. A clip portion is rotatably attached to the holster section and formed to have a circular opening with at least one detent along an inner perimeter of the opening. A spring system is coupled to the holster section and includes a substantially incompressible piston and a compressible material separate from and coupled to the substantially incompressible piston. The circular opening is sized to fit around the spring system. The holster section is formed to have at least one protrusion, and the substantially incompressible piston and the compressible material are insertable against the protrusion, whereby the at least one protrusion contributes to holding the substantially incompressible piston and the compressible material in place relative to the holster section.

Abstract: An amplifier system to increase the efficiency of amplification systems that employ linear modulation schemes. The amplifier system has a signal amplifier for receiving a constant amplitude input signal and producing an amplified version of the input signal. A variable impedance network presents various impedances to an output of the signal amplifier responsive to a load control signal. An envelope mapping circuit coupled to the variable impedance network produces the load control signal responsive to a desired amplitude modulation (AM) envelope. The various impedances causes the desired AM envelope to be impressed upon the amplified version of the input signal.

Abstract: A method of making a geographic location determination via a cellular telephone in signal communication with a base station. The mobile station first attempts to detect a position location signal. Upon determining that the position location signal is insufficient to use in a position location calculation, the mobile station deactivates at least a portion of a receiver. The mobile station receives a cellular communication signal and measures a signal quality of the cellular communication signal. Responsive to the signal quality improving by a predetermined amount, the mobile station reactivates the receiver portion and re-attempts to detect the position location signal.

Abstract: A radiotelephone (200) has a display (208) that efficiently presents information such as lists and text fields. For each list, the display (208) presents a title message (300) with unique identification markings (332,334), an end-of-list indicator (340), and a dynamic scroll indicator (308) to indicate scrolling directions. A context-sensitive symbol (306) is displayed whenever a context sensitive menu is available for a highlighted item. A search function is incorporated to allow expert users to quickly find information. A notepad feature allows the most recent string of user input data to be stored and recalled so that the data is not accidentally appended to subsequently entered data. Specialized data entry modes such as an editor screen (900), an editor-with-list screen sequence, a set value list screen sequence, a toggle value screen sequence, and a form screen sequence provide efficient retrieval, display, and entry of information.

Abstract: A portable unit (101) may both place and receive calls in both the cordless (115) and cellular (103) telephone system. A portable unit (101), in combination with a cordless base station (115), can automatically route an incoming call to the telephone system in which the portable unit (101) is located without inconveniencing the user. Additionally, the portable unit (101), in combination with the cordless base station (115), can automatically route a call in process with the portable unit (101) between the cordless (115) and the cellular (103) telephone systems when the portable unit (101) relocates therebetween.

Abstract: A cellular telephone (110) forms part of a wireless communication system (100) and has simultaneous communication of radio and cellular signals. The wireless communication system (100) has a base station (115) and one or more radios (120). The cellular telephone (110) has control circuitry (205), a cellular transceiver (215), a radio transceiver (210), a microphone (220), and a speaker (225). The simultaneous communication of radio and cellular signals permits a radio user to participate in a cellular phone call and permits a cellular telephone user to participate in the radio communication. Simultaneous communication is communication of cellular and radio signals at the same time and at substantially the same time.

Abstract: A load envelope following (LEF) amplifier system to increase the efficiency of amplification systems that employ linear modulation schemes. The LEF system has a signal amplifier for receiving an input signal that has an amplitude modulation (AM) envelope. The signal amplifier produces an amplified version of the input signal. A variable impedance network is coupled to an output of the signal amplifier and substantially continuously presents various impedances to the output of the signal amplifier in response to a load control signal. An envelope mapping circuit is coupled to the variable impedance network to produce the load control signal in response to and indicative of the substantially continuously varying amplitude of the AM envelope of the input signal.

Abstract: A modulation format switch in signal communication with an amplifier, which produces a plurality of modulation format signals, and a load is described. The modulation format switch includes at least one matching network in signal communication with the amplifier and the load, where the at least one matching network capable of having a plurality of impedance values corresponding to the plurality of modulation format signals. The modulation format switch also includes a controllable element in the matching network, the controllable element capable of having more than one impedance value.