Abstract: An output power control system prevents saturation by limiting total output power and maintaining closed loop responsiveness for a radio telephone having closed loop and open loop gain control systems. The output power control system determines when total output power exceeds an output power trigger level and automatically enters a saturation prevention mode whereby total output power is reduced through modification of a closed loop power control register. In one embodiment, an output detector and an output comparator continuously monitor output power, and in another embodiment, an analog-to-digital converter samples output power levels.

Abstract: A variable attenuator circuit provides variable attenuation responsive to received signal strength in a receiver to reduce intermodulation (IM) distortion. In a dual-mode frequency modulation/code division multiple access (FM/CDMA) cellular telephone implementation, the variable attenuator circuit decreases IM distortion by variably attenuating received radio frequency (RF) signals before an initial RF amplification stage to reduce the level of undesirable frequency mixing products. The variable attenuator circuit is turned on (activated) and off (deactivated) at a single, relatively low, input power level. An attenuator enable signal is also supplied from a logic unit of the mobile station to enable operation of the variable attenuator circuit throughout operation in a digital mode.

Abstract: A variable attenuator circuit provides variable attenuation responsive to received signal strength in a receiver to reduce intermodulation (IM) distortion. In a dual-mode frequency modulation/code division multiple access (FM/CDMA) cellular telephone implementation, the variable attenuator circuit decreases IM distortion by variably attenuating received radio frequency (RF) signals before an initial RF amplification stage to reduce the level of undesirable frequency mixing products. The variable attenuator circuit is turned on (activated) and off (deactivated) at a single, relatively low, input power level. An attenuator enable signal is also supplied from a logic unit of the mobile station to enable operation of the variable attenuator circuit throughout operation in a digital mode.

Abstract: A variable attenuator circuit provides variable attenuation responsive to received signal strength in a receiver to reduce intermodulation (IM) distortion. In a dual-mode frequency modulation/code division multiple access (FM/CDMA) cellular telephone implementation, the variable attenuator circuit decreases IM distortion by variably attenuating received radio frequency (RF) signals before an initial RF amplification stage to reduce the level of undesirable frequency mixing products. The variable attenuator circuit is turned on (activated) and off (deactivated) at a single, relatively low, input power level. An attenuator enable signal is also supplied from a logic unit of the mobile station to enable operation of the variable attenuator circuit throughout operation in a digital mode.