The power amplifier is designed for wireless LAN with integrated power detector. It is important for the power detection to control the output power in order to increase the efficiency of the low output power. But most of power detector has some loss of output power. This thesis shows the power detector network with the low output power loss. The RF base current of power stage is sensed, amplified by the power detector. The power detector gives the detector voltage related to output power. The design of power amplifier utilizing InGaP/GaAs HBT is presented. The power transistor in power amplifier has split R/C base ballasting; it makes the power gain of power amplifier increased. This transistor is designed, measured for large signal modeling. The large signal model contains self-heating effect and ambient temperature effect. For estimating these temperature effects, thermal parameter is extracted. Extracted model is used for power amplifier design. The circuit size is 1.2Ⅹ1.0㎟ In measurement result, the power amplifier with power detection is suited to wireless LAN.
