Matsushita Electric Industrial Co., Ltd.

Panasonic Corporation

Masahiko Inamori

Kaname Motoyoshi

Masao Nakayama

Kazuki Tateoka

Haruhiko Koizumi

Tsunehiro Takagi

Hirokazu Makihara

Shingo Matsuda

Takashi Yamamoto

Katsushi Tara

Hiroshi Sugiyama

Kazuhiko Ohhashi

Junji Kaido

Motoyoshi Iwata

Shinichi Sonetaka

Shingo Enomoto

Hiroaki Kawano

Satoshi Makioka

Katuhiko Kawashima

Singo Matsuda

Kenta Matsui

Singo Enomoto

Shingo Matuda

Kazuhiko Ohashi

Masahiro Hagio

A semiconductor device and a radio frequency circuit which are appropriate for multiband, multimode performance can be realized as a semiconductor device including a field-effect transistor formed on a semiconductor substrate, and include: ohmic electrodes serving as source and drain electrodes of the field-effect transistor, first and second Schottky electrodes provided between the ohmic electrodes and serving as gate electrodes of the field-effect transistor, and a third Schottky electrode provided and grounded between the first and second Schottky electrodes.

Semiconductor device, radio frequency circuit, and radio frequency power amplifier

An RF power amplifier according to an implementation of the present invention includes: a first power amplifier which linearly amplifies a first RF signal of a first frequency band; a second power amplifier which linearly amplifies a second RF signal of a second frequency band lower than the first frequency band; a third power amplifier which nonlinearly amplifies a third RF signal of the first frequency band; a fourth power amplifier which nonlinearly amplifies a fourth RF signal of the second frequency band, and input lines of the respective power amplifiers do not cross each other on semiconductor substrates, and the output lines of the respective power amplifiers do not cross each other on the semiconductor substrates.

Radio frequency power amplifier

A first FET is inserted in a series position between a signal input terminal and a signal output terminal, while second and third FETs are inserted in a shunt position respectively between the signal input terminal and a ground terminal and between the signal output terminal and a ground terminal. First and second reference voltage terminals and a control terminal are provided. A first reference voltage and a control voltage are applied to the first FET, while a second reference voltage and a control voltage are applied respectively to the second and third FETs, so that the first, second, and third FETs serve as variable resistors. As such, a gain control circuit is constructed. Further, a first resistor is provided in parallel to the first FET, while second and third resistors are provided respectively in series to the second and third FETs.

High frequency amplifier circuit and mobile communication terminal using the same

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.

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 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.

High 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 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 high frequency part, which amplifies a high frequency signal outputted from an intermediate frequency part and supplies to an antenna, is equipped with a gain controller with switch function. The gain controller with switch function comprises an attenuator with switch function has a function of switching a selected band between two bands outputted from the intermediate frequency part and controlling the gain of the high frequency signal in the selected band. The attenuator with switch function comprises a first variable resistor which connects a signal input part with a signal output part and a second variable resistor which is disposed parallel to said first variable resistor and connects a signal input part with a signal output part. The first and the second variable resistors are controlled by a common gain control voltage and set such that the gain control voltage ranges, which are for changing the resistor values, will not overlap with each other.

Attenuator with switch function and mobile telephone terminal device using the same

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

A bias voltage is applied via a first resistance to the base of a first transistor, and a radio frequency signal is input via a first capacitor to the base of the first transistor. The bias voltage is applied via a second resistance to the base of a second transistor. The bias voltage is applied via a third resistance to the base of a third transistor, and the radio frequency signal RF is input via a third capacitor to the base of the third transistor. A first band rejection filter is provided between the base of the first transistor and the base of the second transistor. A second band rejection filter is provided between the base of the second transistor and the base of the third transistor. The collectors of the first to third transistors are connected in common and the emitters thereof are all grounded.

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 gain control circuitcomprises an FEToperating as a variable resistor. A gate terminal of the FETis supplied with a control voltage VC applied to a gain control terminal. A source terminal and a drain terminal of the FETare supplied with a reference voltage Vrefobtained by a reference voltage circuit. The reference voltage Vrefis controlled so as to compensate for a variation in the threshold voltage of the FET. The resistance value of the FETis changed in accordance with the control voltage VC, and thus the gain of the high frequency amplification circuitis also continuously changed.

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Ibaraki, Japan

Masahiko Inamori