Panasonic Corporation

Matsushita Electric Industrial Co., Ltd.

Hirokazu Makihara

Kazuki Tateoka

Masahiko Inamori

Shingo Matsuda

Haruhiko Koizumi

Katsuhiko Kawashima

Shingo Enomoto

Junji Kaido

Shingo Matuda

Katuhiko Kawashima

Singo Matsuda

Kenta Matsui

Singo Enomoto

A radio frequency signal is input to the bases of transistors via respective capacitors, is amplified, and is output from the collectors of the transistors. The emitter of each transistor is grounded. A bias current input from a bias circuit is supplied to the bases of the transistors via respective resistors both during low-output operation and during high-output operation. The collectors of the transistors are connected via an impedance circuit to a bias voltage input terminal. Therefore, during high-output operation, a direct current offset voltage is generated by the impedance circuit based on a portion of a radio frequency signal output from the collectors, thereby further increasing the bias current.

Radio frequency power amplifier

A bias circuit operable to supply a bias current to a first transistor includes: a second transistor having a collector terminal connected to a first power supply; a first resistance element having one end connected to an emitter terminal of the second transistor and having the other end connected to a base terminal of the first transistor; a second resistance element having one end connected to the emitter terminal of the second transistor and having the other end connected to ground potential; at least one third resistance element provided between a base terminal of the second transistor and a second power supply; and a plurality of temperature compensation circuits connected to the base terminal of the second transistor which are operable to control a base potential of the second transistor so that the potential falls as a temperature rises.

Radio-frequency power amplifier

A radio-frequency power amplifier for preventing a final-stage HBT from being destroyed is provided. To this end, a radio-frequency multistage power amplifier of the present invention includes: a first amplification stage having a first hetero bipolar transistor of which collector output is detected; a second amplification stage which is prior to the first amplification stage and which has a second hetero bipolar transistor in which the detection result is reflected; a first resistor provided between a collector of the second hetero bipolar transistor and a power supply; and a protection circuit which is connected between a collector of the first hetero bipolar transistor and the collector of the second hetero bipolar transistor, detects output from the collector of the first hetero bipolar transistor, and reduces a voltage of the collector of the second hetero bipolar transistor in accordance with the detected output.

A radio frequency power amplifierincludes a former-stage transistor, a latter-stage transistor, and an inter-stage matching circuitfor connecting the former-stage transistorand the latter-stage transistor. The inter-stage matching circuitincludes a high-pass filter circuit including a transfer line m, a capacitor Cand a capacitor C; and a transfer line mwith which a passage phase of a secondary harmonic signal is 15 degrees or greater.

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.

A high-frequency power amplifier with a temperature compensation function for power amplifying a high-frequency signal, includes: a power amplifying transistor having an emitter grounded; a high power output bias circuit that supplies a high power output current corresponding to a high power output of the high-frequency power amplifier to the power amplifying transistor; and a low power output bias circuit that supplies a low power output current corresponding to a low power output of the high-frequency power amplifier to the power amplifying transistor.

High-frequency power amplifier

The transistor circuitincludes a plurality of transistor cellseach having a transistor, a base ballast resistor, a capacitor, and an inductor. The transistorshave the respective collectors commonly connected to a collector terminalof the transistor circuitand the respective emitters commonly connected to an emitter terminalthereof. Each base ballast resistoris connected to bases of the transistorat one end and to a base terminalof the transistor circuitat the other end. The capacitoris serially connected to the inductor, thus to form a serial resonant circuit, which is connected in parallel with the base ballast resistorand provided between the bases of the transistorand the base terminalof the transistor circuitand connected thereto.

Growing community of inventors

Osaka, Japan

Hirokazu Makihara