Panasonic Corporation

Nuvoton Technology Corporation Japan

Matsushita Electric Industrial Co., Ltd.

Panasonic Semiconductor Solutions Co., Ltd.

Panasonic Intellectual Property Management Co., Ltd.

Shingo Matsuda

Kazuki Tateoka

Hirokazu Makihara

Kaname Motoyoshi

Masahiko Inamori

Masatoshi Kamitani

Kouki Yamamoto

Takashi Saji

Katsuhiko Kawashima

Masao Nakayama

Haruhiko Koizumi

Hiroshi Sugiyama

Masahiro Maeda

Shinichiro Ishitsuka

Shigeru Kataoka

Kenji Hirai

Hiroaki Kawano

Junji Kaido

Ichiro Kato

Wataru Kanaga

Kazuhiko Ohashi

A high-frequency amplifier includes: a carrier amplifier which amplifies a first signal; a peak amplifier which amplifies a second signal; a first matching circuit which is connected to the output terminal of the carrier amplifier; a second matching circuit which is connected to the output terminal of the peak amplifier; a first transmission line which is connected between the first matching circuit and the second matching circuit, and has an electric length that is less than ¼ of the wavelength of the center frequency of a predetermined frequency band. The phase rotation by a series inductor which is included in each of the first matching circuit and the second matching circuit and has one end that has been grounded is opposite to the phase rotation by the first transmission line.

High-frequency amplifier

A power amplifier device includes: a first power supply terminal for inputting a first power supply voltage; a first transistor for power amplification that (i) includes a first gate to which a bias voltage is applied, and (ii) is supplied with power from the first power supply terminal; a second power supply terminal for inputting a second power supply voltage lower than the first power supply voltage; a second transistor for monitoring that (i) includes a second gate to which the bias voltage is applied, (ii) is supplied with power from the first power supply terminal or the second power supply terminal, and (iii) imitates an operation of the first transistor; and a bias circuit that is supplied with power from the second power supply terminal and generates and adjusts the bias voltage according to a drain current or a source current of the second transistor.

Power amplifier device

A high-frequency transistor includes a source electrode, a drain electrode, a gate electrode, and a gate drive line that applies a voltage to the gate electrode. An impedance adjustment circuit is connected between the gate electrode and the gate drive line. A characteristic impedance of the gate electrode is Z1, when a connecting point between the impedance adjustment circuit and the gate electrode is viewed from the impedance adjustment circuit. A characteristic impedance of the gate drive line is Z2, when a connecting point between the impedance adjustment circuit and the gate drive line is viewed from the impedance adjustment circuit. X that denotes a characteristic impedance of the impedance adjustment circuit is a value between Z1 and Z2.

High-frequency transistor

A high-frequency amplifier includes: a carrier amplifier amplifying a first signal; a peak amplifier amplifying a second signal; a first transmission line connected between output terminals of the carrier amplifier and the peak amplifier, and having an electrical length equal to one-quarter wavelength of a center frequency in the predetermined frequency band; a second transmission line connected between one end of the first transmission line and the output terminal of the high-frequency amplifier, and having an electrical length equal to one-quarter wavelength of the center frequency; and an impedance compensation circuit with one end connected to a node between the first transmission line and the second transmission line. At the center frequency, an imaginary part of an impedance during viewing of the impedance compensation circuit from the node is opposite in polarity from an imaginary part of an impedance during viewing of the second transmission line from the node.

A semiconductor device includes a source electrode portion and a drain electrode formed on a semiconductor stacked body so as to be at an interval from each other, and a gate electrode formed between the source electrode portion and the drain electrode at an interval from the source electrode portion and the drain electrode. The source electrode portion includes a first recess electrode being directly in contact with a two-dimensional electron gas layer formed in the first nitride semiconductor layer, and a surface electrode formed between the gate electrode and the first recess electrode and connected conductively to the two-dimensional electron gas layer. A source potential is applied to the surface electrode and the recess electrode, and a width of the surface electrode in a gate-source direction is 0.4 times or more a distance between a gate-side end of the surface electrode and a source-side end of the gate electrode.

Semiconductor device

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 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 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.

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.

Transistor circuit

An amplifieramplifies a transmission signal, and outputs the amplified signal to an antenna. A directional couplercauses a portion of power passing through a first path connecting the amplifierand the antenna to branch to a second path. A detection sectiondetects an electrical parameter changing with a change in the intensity of power reflected from the antenna to the amplifier, thereby detecting the intensity of the reflected power. A control circuitchanges a proportion of power caused to branch to the second path by the directional coupler, based on the electrical parameter detected by the detection circuit. Thus, it is possible to provide a reflected power suppression circuit capable of facilitating size reduction and preventing a power amplifier from being damaged due to breakage of an antenna, while minimizing a power loss at the time of signal transmission.

Reflected power suppression circuit

An object of the present invention is to provide a fluorescent lamp including: a hermetically sealed lamp vessel; and a phosphor layer attached to a part of an inner surface of the lamp vessel, where a thickness of the phosphor layer near an edge thereof gradually and smoothly decreases towards the edge.

Growing community of inventors

Kyoto, Japan

Shingo Matsuda