Matsushita Electric Industrial Co., Ltd.

Panasonic Corporation

Haruhiko Koizumi

Masahiko Inamori

Kazuki Tateoka

Hirokazu Makihara

Kaname Motoyoshi

Shingo Matsuda

Shingo Enomoto

Katsushi Tara

Kunihiko Kanazawa

Masao Nakayama

Akihisa Sugimura

Tsunehiro Takagi

Hiroaki Kawano

Kazuya Wakita

Kazuhiko Ohashi

Shingo Matuda

Katuhiko Kawashima

Singo Matsuda

Kenta Matsui

Singo Enomoto

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

Provided are a detector circuit which has a simple circuit configuration, is capable of indicating an accurate power according to a load fluctuation of a radio frequency power amplifier or a difference in a modulation mode, and can be easily incorporated in the radio frequency power amplifier, and a wireless communication system using the detector circuit. The detector circuitincludes a detecting resistorfor detecting a part of a current flowing from a bias circuit, and a current-voltage conversion circuitfor converting a current obtained through the detecting resistorinto a voltage. A current supplied from the bias circuitto the amplifying transistoris detected, so that an output current from the amplifying transistorfluctuates when a load on the radio frequency power amplifier fluctuates, and an input current and a current from the bias circuit fluctuate in proportion to the output current from the amplifying transistor, whereby an outputted detection voltage can follow a load fluctuation on the radio frequency power amplifier.

Detector circuit and system for a wireless communication

A small, high performance high frequency power amplifier enables easily adjusting and switching the impedance. The high frequency power amplifier module includes a first semiconductor chip including one or a plurality of high frequency amplification devices, and a second semiconductor chip including one or more high frequency matching circuit devices and one or more switching devices. The second semiconductor chip includes the matching circuit for a high frequency amplifier device. The second semiconductor chip also includes a circuit composed of a capacitance and a switching device connected in series or parallel to the capacitance. The switching device switches on or off so that the capacitance is connected or is not connected as a part of the matching circuit.

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.

Radio-frequency power amplifier

A small, high performance, multifunctional high frequency circuit that is multiband and multimode compatible reduces loss from a switch formed on the output side of a final stage amplification unit. The final stage amplification unit power amplifies an input signal and outputs an amplified signal. A first matching circuit impedance converts the amplified signal input thereto at a first input impedance, and outputs a first impedance-converted signal at a first output impedance. A control unit that generates a control signal denoting signal path selection information. A switch unit selects one of at least two signal paths based on the control signal, passes the first impedance-converted signal at an on impedance through the selected path, and outputs the pass signal. A second matching circuit impedance converts a pass signal input thereto at a second input impedance, and outputs a second impedance-converted signal at a second output.

High frequency circuit, semiconductor device, and high frequency power amplification 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

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

An output level of a transmission apparatusis determined, depending on an attenuation amount of an attenuator, a gain of one of a high output level amplification sectionand a low output level amplification section, which is used. A reference voltage Vref(H) is discontinuously changed. Depending on the magnitude of the reference voltage Vref(H), it is determined which of the amplification sectionsis used, and the attenuation amount of the attenuatorand the gain of the amplification sectionare also determined. When the magnitude of the reference voltage Vref(H) is changed, a sum of the attenuation amount of the attenuatorand a gain change amount of a switch amplification sectionis substantially zero.

Transmission apparatus and mobile communication terminal apparatus

A high frequency amplifier circuit has a bias supplying transistor for supplying a bias current to an amplifying transistor, and first and second temperature compensating transistors for compensating the temperature properties of the base voltage of the bias supplying transistor. The base of the bias supplying transistor and the base of the first temperature compensating transistor are connected by a resistor in order to keep the base voltage of the bias supplying transistor approximately constant without following a change in the base voltage of the first temperature compensating transistor, even in the case where such a change occurs. The temperature compensating transistors, the bias supplying transistor and the resistor are formed in one multi-emitter type transistor.

High frequency amplifier circuit

The present invention provides a frequency conversion circuit capable of reducing current without impairing high frequency characteristics. A local oscillator amplifier is formed of a first field effect transistor. A source thereof is grounded by a first capacitor in terms of high frequency, and a gate thereof is connected to one end of each of first and second resistors. The other end of the first resistor is grounded, and the other end of the second resistor is connected to a voltage supply terminal. An intermediate frequency amplifier is formed of a second field effect transistor. A source thereof is grounded through a third resistor and a second capacitor that are connected in parallel with each other. A drain thereof is connected to an intermediate frequency signal output terminal through a third capacitor and an intermediate frequency output matching circuit. The source of the first field effect transistor and the drain of the second field effect transistor are connected through an AC blocking circuit.

Frequency conversion circuit

A frequency converter includes: a first terminal through which a local oscillator signal is input; a second terminal through which an input signal with a frequency to be converted is input; a third terminal through which an output signal with a different frequency resulting from the conversion is output; and a field effect transistor with gate, source and drain terminals for converting the frequency of the input signal and outputting the signal with the different frequency as the output signal. The gate terminal is connected to the first terminal, while the drain terminal is connected to the second and third terminals. The frequency converter further includes a trap circuit, which resonates at a frequency of a harmonic of the local oscillator signal to substantially eliminate the harmonic.

Frequency converter

In a dual-mode radio telephone transmitter operative in both an analog modulation mode based on the FDMA system and a digital modulation mode based on the TDMA system, a DC bias voltage Vdd to be applied to a power amplification circuit is varied in accordance with the type of modulation, so that the input/output characteristics of the power amplification circuit can be optimized. To this end, a micro processor controls a switch interposed between the power amplification circuit and a positive DC power unit in such a manner that the DC bias voltage Vdd is 4.8 V for the FDMA mode, while the DC bias voltage Vdd is 6.0 V for the TDMA mode. The value of another DC bias voltage Vgg in the power amplification circuit is fixed. The value of the DC bias voltage Vdd is set higher in the TDMA mode than in the FDMA mode; thus, it becomes possible to increase the power added efficiency in the FDMA mode, without adversely affecting high linearity and high efficiency in the TDMA mode.

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Osaka, Japan

Haruhiko Koizumi