Panasonic Corporation

Panasonic Intellectual Property Management Co., Ltd.

Shingo Enomoto

Haruhiko Koizumi

Kazuya Wakita

Masahiko Inamori

Masatoshi Kamitani

Kazuki Tateoka

Motoyoshi Iwata

Hirokazu Makihara

Masato Seki

Hiroaki Kawano

Shinichiro Ishihara

Shingo Matuda

Katuhiko Kawashima

A power amplifier includes an amplification transistor which performs power amplification, a bias circuit which outputs a bias voltage to a base of the amplification transistor, a control terminal to which a control voltage is applied for controlling switching between an operating state and a stopping state of the bias circuit, and a bias voltage adjustment circuit connected to the control terminal. The bias voltage adjustment circuit includes a variable capacitance element which is connected to the control terminal and whose capacitance value decreases as the control voltage increases, a discharge circuit which discharges electric charge accumulated in the variable capacitance element to the control terminal, and a control circuit which is connected to the bias circuit and controls the bias voltage. The bias voltage adjustment circuit outputs, to the bias circuit, a bias voltage adjustment signal which increases the bias voltage for a predetermined period after the control voltage is applied.

Power amplifier

Provided is a compact high frequency power amplifier having a high degree of freedom of design with respect to a gain fluctuation immediately after start-up of an amplifier. The high frequency power amplifier includes a speed-up circuit that transiently increases a reference voltage during rise of a control voltage to increase an amount of bias supplied to an amplification transistor from a bias circuit. The speed-up circuit includes a capacitor and an overshoot control circuit. The overshoot control circuit determines an increasing amount of the reference voltage when the reference voltage is transiently increased according to a charge amount charged in the capacitor, and the overshoot control circuit also determines a time constant in charging and discharging the capacitor.

High frequency power amplifier

It is an object of the present invention to provide a high-frequency power amplifier capable of improving the linearity at the time of high output by preventing decrease in power of bias supply transistor. The high-frequency power amplifier is a high-frequency power amplifier including high-frequency power amplifier transistors and connected in multiple stages and bias supply transistors and each of which supplies bias current to a base of a corresponding one of said high-frequency power amplifier transistors, and each of which is connected to a common power supply terminal which is further connected to a collector of the high-frequency power amplifier transistor at a first stage among said high-frequency power amplifier transistors, and a passive element connected between the common supply terminal and a collector of the corresponding one of said bias supply transistors connected to the high-frequency power amplifier transistor at the first stage.

High-frequency power amplifier and communication device

A radio frequency signal RF is input to a base of each of transistors TRthrough TRn via a corresponding capacitor among capacitors Cthrough Cn, is amplified, and is output from a collector of each of the transistors TRthrough TRn. An emitter of each of the transistors TRthrough TRn is grounded. A bias voltage DC given from a bias circuit Bias is supplied to the base of each of the transistors TRthrough TRn via a corresponding resistor among resistors Rathrough Ran. A signal line for the bias voltage DC is connected to an input line for the radio frequency signal RF via the bridge resistor R in a direct current manner.

Radio frequency power amplifier

Growing community of inventors

Osaka, Japan

Shingo Enomoto