Patent ID: 6603351
Filing Date: 2003-08-05
Classification: H03F

Abstract:
A power amplifier comprising:(a) first to n-th amplifier stages connected in cascade, where n is an integer greater than unity; (b) a k-th one of the amplifier stages receiving a k-th input signal power to produce a the output signal power, where k is an integer satisfying a relationship of 1&lE;k&lE;n; the k-th amplifier stage including a transistor with an amplification function; the transistor having a gain change in a range of the k-th input signal power or the k-th output signal power; (c) a m-th one of the amplifier stages receiving a m-th input signal to produce a m-th output signal, where m is an integer satisfying a relationship of 1&lE;m&lE;n and mâ‰ k; the m-th amplifier stage including a transistor with an amplification function; the transistor having a gain change in a range of the m-th input signal power or the m-th output signal power; and (d) the gain change of the transistor of the m-th amplifier stage being decreased or cancelled by the gain change of the transistor of the k-th amplifier stage.