摘要:
A portable wireless transceiver (104) includes a receiver (206) for monitoring transmissions from neighboring transceivers (106A and 106B) to select a transceiver to use for communications. The portable wireless transceiver (104) further has a motion detector (204) for determining whether or not the portable wireless transceiver (104) is moving. If the portable wireless transceiver (104) is determined to not be moving, a processor (202) alters a schedule for monitoring of neighboring transceivers (106A and 106B) so that the monitoring is performed less frequently, thereby reducing power consumption by the portable wireless transceiver (104).
摘要:
A loop antenna (100) shares terminals with a thermistor on a battery. The battery (300) has at least two terminals (302 & 304) that connect to a thermistor (514). An electromagnetic wave radiating and receiving element (522) shares the at least two terminals (302 & 304) with the thermistor (514) but is electrically isolated from the thermistor (514) so that the thermistor (514) resistance can be measured while the electromagnetic wave radiating and receiving element (522) can communicate electrical RF signals via the at least two terminals with an RF circuit. A wireless communication device that uses the battery (300) and the loop antenna (100) is also disclosed.
摘要:
A radio transceiver (100) has both a radio frequency power amplifier (102) and a relatively high output audio power amplifier (110). The RFPA amplifies a linearly modulated signal. A shared power regulator (108) provides supply voltage to both amplifiers at the same time. However, usually only one is active at any given time, and hence the supply voltage is controlled so as to follow the envelope of the signal being amplified, whether it is the transmit signal or the audio signal. When both amplifiers are active, the supply voltage can be set to a fixed level, or it can follow the higher of the two envelopes.
摘要:
An amplifier apparatus for a multimode mobile communication device includes a carrier amplifier (114) and a peaking amplifier (116). The peaking amplifier has an adjustable bias level and is adjusted by a regulator to a predetermined level, depending on which mode of communication is selected. The bias level on the peaking amplifier is held constant so long as the mode of communication is the same. By adjusting the bias point of the peaking amplifier in conjunction with the selection of the mode of communication, the efficiency and the linearity of modulation can be optimized for the particular mode of communication.
摘要:
The RF section of a communication device (100) includes a receiver (106), a transmitter (108), first injection frequency generation circuit (120), and an intermediate frequency (IF) generation circuit (124). The IF generation circuit has a shared output coupled to both the receiver and transmitter, as well as a control circuit (118) for feedback control purposes. The IF generation circuit is used to generate IF for both the receiver and transmitter, thus using fewer components that two separate IF generation circuits. It includes two differently tuned voltage controlled oscillators (202, 204) which are selectively and exclusively powered by first and second power switches (234, 236), respectively. The control circuit provides a single control voltage corresponding to a desired frequency pair to both VCOs at a common control input, then selects the appropriate VCO depending on whether the communication device is receiving or transmitting.
摘要:
A method and apparatus for biasing the voltage controlled oscillator (VCO) (110) of a Phase Locked Loop (PLL) (100) includes a bias circuit (114) providing a peak minimum/maximum voltage detector (202) tied to the control line (116) of the PLL (100). During operation, the detector (202) detects a minimum or maximum voltage on the VCO control line (116) as the bias control voltage (118) applied to the VCO (110) is varied. Detection of such a minimum or maximum voltage is equivalent to the detection of a minimum or a maximum frequency, which in turn equates to the detection of an optimal bias condition for noise.
摘要:
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.
摘要:
A portable radio (306) provides a selectable and/or automatic battery conditioning mode of operation (400). Battery conditioning is achieved by discharge state (410) that discharges the battery down to a predetermined threshold using existing radio circuitry (308).
摘要:
A dual band VCO selects between the oscillator output frequencies by switching the resonant circuit elements in the active circuit. For each output frequency selected, the oscillator produces a single frequency signal and additional energy in the form of phase noise. This phase noise may be from sideband noise produced by modulation of the single frequency or produced by the active device in the oscillator as flicker noise, or the noise figure of the active device under large signal conditions or the filtering effect or the resonant circuit. Phase noise is reduced by shifting the bias point for the active device to the level where phase noise is minimum for each output frequency. At the time the output frequency is selectively switched, the bias to the active device is selectively switched to an optimum bias level for minimum phase noise for each respective selected frequency.
摘要:
A multi-mode communication device (100) uses a first wireless modem (118) and a second wireless modem (120) which operates independently to facilitate communication over different air interfaces. Both modems are powered by a common battery (105). When the first wireless modem engages in a communication activity, the second wireless modem's maximum operating power level is reduced. When the first wireless modem ceases communication activity, the second wireless modems full operating power range is restored.