Patent ID: 6434373
Filing Date: 2002-08-13
Classification: H03G

Abstract:
A transmission power control device for use in a radio communication apparatus, comprising:processing means for processing an input transmission signal into a processed transmission signal; power amplifying means having a first transistor for amplifying said processed transmission signal into a power amplified transmission signal; said processing means processing said input transmission signal into the processed transmission signal in accordance with a control signal which is independent of the power amplified transmission signal; detecting means for detecting a current flowing through said first transistor to produce a current detection signal; converting means for converting the control signal into a reference value signal corresponding to a level of said processed transmission signal, said reference value signal being representative of a reference value of a bias current of said first transistor each time transmission power of said power amplified transmission signal is varied; and bias current means for comparing said current detection signal with said reference value signal to produce a comparison result signal, said bias current means varying said bias current in accordance with said comparison result signal to reduce said bias current on decreasing said transmission power.