Abstract: A system and method for detecting compression of power amplifier circuitry in a wireless terminal and, in response, reducing the output power of the power amplifier circuitry such that linear operation is achieved. In general, the output power of the power amplifier is detected to provide a detect signal. The detect signal is sampled at two predetermined points in time. A ratio of the samples of the detect signal is compared to an expected ratio. Based on the comparison, a decision is made as to whether the power amplifier circuitry is in compression. If so, an adjustable power control signal controlling the output power of the power amplifier circuitry is reduced by one power step, such that the output power of the power amplifier circuitry is reduced by one output power level. The process is repeated until the power amplifier circuitry returns to linear operation.

Abstract: The present invention provides for power amplifier control of amplifier circuitry including an input stage and one or more output stages. The input stage is powered separately from the output stage by a relatively fixed power source. The one or more output stages are supplied with power via a voltage regulator having a controllable output voltage. A closed loop control integrated with the amplifier stages forces the voltage output of the voltage regulator to track the profile of an adjustable control signal, such as VRAMP.

Abstract: The present invention provides for power amplifier control of amplifier circuitry including an input stage and one or more output stages. The input stage is powered separately from the output stage by a relatively fixed power source. The one or more output stages are supplied with power via a voltage regulator having a controllable output voltage. A closed loop control integrated with the amplifier stages forces the voltage output of the voltage regulator to track the profile of an adjustable control signal, such as VRAMP.

Abstract: The present invention provides power amplification circuitry having multiple amplifier stages in series and adapted to facilitate polar modulation. As such, the amplifier circuitry receives a frequency signal representing the frequency and phase components of the signal to be transmitted, as well as an amplitude signal presenting the amplitude component of the signal to be transmitted. The frequency component is amplified by the amplification circuitry. The amplitude component controls the supply voltage provided to the amplifier stages in the amplification circuitry. To increase the dynamic range of the amplification circuitry, the final stage or stages of the amplification circuitry are selectively disabled when lower output powers are necessary, and enabled when higher output powers are required.

Abstract: The present invention provides for power amplifier control of amplifier circuitry including an input stage and one or more output stages. The input stage is powered separately from the output stage by a relatively fixed power source. The one or more output stages are supplied with power via a voltage regulator having a controllable output voltage. A closed loop control integrated with the amplifier stages forces the voltage output of the voltage regulator to track the profile of an adjustable control signal, such as VRAMP.

Abstract: An apparatus for providing an antenna impedance matching network that does not include mechanical switch contacts is disclosed. A retractable antenna includes a conductive plate moveable between the extended and retracted positions of the antenna. When the conductive plate is located in the extended position an impedance matching circuit responsive to the position of the conductive plate is connected between the antenna and an amplifier of a radio telephone. In response to location of the conductive plate in the retracted position, the impedance matching circuit is shorted out such that the antenna is connected directly to the amplifier via a capacitive effect between the conductive plate and a conductive coil of the shorted out impedance matching circuit.

Abstract: An antenna assembly, and an associated method, facilitates communication of a radiotelephone operable in a satellite communication system, such as a satellite-cellular communication system. A patch antenna is rotatably coupled to a radiotelephonic housing of the radiotelephone. The patch antenna exhibits circular polarization characteristics, best to detect and to transmit communication signals to a satellite-based transceiver. By positioning patch antennas at opposing sides of the radiotelephone, down-link signals transmitted to the radiotelephone are detectable irrespective of the orientation of the radiotelephone.

Abstract: The present invention relates generally to RF power amplifiers for portable cellular radiotelephones, and more particularly, to dual-mode cellular radiotelephones. A power supply network enables the RF power amplifier in a dual-mode radiotelephone to operate with two separate modes: saturated and unsaturated. Switches in the power supply network, e.g. complementary transistors, are driven to a first set of logic states by a square wave which is synchronized with transmit time slots present in a TDMA frame structure to charge a capacitor from a battery. When the switches are then driven to a second set of logic states, the capacitor is placed in series with the battery to essentially double the supply voltage. When the radiotelephone operates in a digital mode, the increased supply voltage coincides with the transmit time slot and temporarily increases the saturation point of the RF power amplifier to permit linear amplification.