Renesas Technology Corp.

Hitachi Hybrid Network Co., Ltd.

Other

Hitachi Ulsi Systems Co., Ltd.

Hiroyuki Nagamori

Takayuki Tsutsui

Yasuhiro Nunogawa

Kouichi Matsushita

Hitoshi Akamine

Shun Imai

Satoshi Arai

Nobuhiro Matsudaira

In radio communication system that is able to transmit in two or more modulation modes, e.g., one modulation mode when phase shifts are performed and another modulation mode when phase shifts and amplitude shifts are performed, the disclosed invention can avoid that receiving band noise becomes so great not to conform to the GSM standards' prescription for such noise in a high voltage region of the power supply voltage, even when the output power is controlled by changing the amplitude of the input signal to the power amplifier circuitry while fixing the bias voltages to be applied to the power amplifying transistors. When the output power is controlled as above, in the modulation mode (GSM mode) when phase shifts are performed, idle currents flowing across the power amplifying transistors are regulated, depending on the power supply voltage, i.e., the idle currents are decreased when the power supply voltage is high and increased when the power supply voltage is low.

High frequency power amplifier component and radio communication system

There are provided an electronic component for high frequency power amplification provided with a high-sensitivity output power detection circuit which is immune to the influence of changes in the use environment thereof, free of an output mismatch, small in size, and low in insertion loss and a wireless communication system using the electronic component. There are provided an output detection transistor which receives, at a control terminal, a voltage extracted from the intermediate node of an impedance matching circuit provided between the final-stage power amplification transistor of a high-frequency power amplification circuit and an output terminal thereof via a capacitor element and allows a current proportional to an output power to flow, a bias generation circuit for giving an operating point to the control terminal of the transistor, a current mirror circuit for transferring the current flowing in the output detection transistor, and a current-to-voltage conversion transistor for converting the transferred current to a voltage.

Electronic component for high frequency power amplifier and radio communication system

A directional coupler for detecting an output of a high frequency circuit module includes a main line and a sub-line overlapped with the main line with a dielectric material. The sub-line is set, in width, narrower than the main line and both side edges of the sub-line are allocated at the internal side of both side edges of the main line. Accordingly, the sub-line is surely provided opposed to the main line in the total width area and a signal current flowing into the main line can be detected in higher accuracy. Therefore, a wireless communication system for controlling an output of the high frequency circuit module by including such directional coupler assures stable communication.

Directional coupler, high frequency circuit module and wireless communication system

A high-frequency power amplification electronic part is disclosed which comprises a power amplifier circuit and a bias control circuit, the power amplifier circuit having a plurality of amplifier stages for amplifying an input high-frequency signal, the bias control circuit acting to bias the power amplifier circuit. The power amplifier circuit controls output power in accordance with input power that is varied while a gain of the power amplifier circuit is being fixed by either a bias current or a bias voltage supplied from the bias control circuit. The bias control circuit supplies at least two diode characteristic elements with a predetermined current each in order to generate at least two voltages demonstrating different temperature characteristics, the bias control circuit further using the generated voltages as a basis for generating either a plurality of bias currents or a plurality of bias voltages having a desired temperature-dependent rate of change each, the generated bias currents or bias voltages being fed to each of the plural amplifier stages constituting the power amplifier circuit.

High-frequency power amplification electronic part and wireless communication system

The present invention provides a high frequency amplifier using a power supply voltage regulate circuit for the purpose of compensating for variations in power supply voltage. The high frequency amplifier comprises three-stage power amplifiers which amplify an input signal and output the amplified signal, a bias circuit which supplies bias voltages for controlling these power amplifiers, a regulate circuit which compensates for variations in noise or gain with respect to the variations in the power supply voltage for driving the power amplifiers, etc. The regulate circuit holds constant an output voltage Vddc with respect to variations in power supply voltage Vdd and outputs the constant-held output voltage Vddc as a power supply voltage for the power amplifiers.

Growing community of inventors

Komoro, Japan

Hiroyuki Nagamori