Patent Number: 6,297,694

Title: High frequency power amplifier

Abstract: A dual band system high frequency power amplifier has biasing circuits and a bias switching circuit, each circuit having heterojunction bipolar transistors (HBTs) so that the high frequency power amplifier can be integrated with an MMIC of HBTs. A bias switching circuit for switching a first biasing circuit and a second biasing circuit, each made with HBTs, is built with common AlGaAs or GaAs HBTs, having three or more such HBTs connected in series so that the total of each base-emitter voltage, Vbe, does not exceed 3 V.

Inventors: Yamamoto; Kazuya (Tokyo, JP)

Assignee: Mitsubishi Denki Kabushiki Kaisha

International Classification: H03F 3/20 (20060101); H03F 3/189 (20060101); H03F 3/21 (20060101); H03F 3/72 (20060101); H03F 3/19 (20060101); H04Q 7/38 (20060101); H03F 001/14 ()

Expiration Date: 10/02/2018