Hitachi, Ltd.

Hitachi Medical Corporation

Renesas Electronics Corporation

Renesas Technology Corp.

Other

Hitachi Communication Systems, Inc.

Hitachi Communications Systems, Inc.

Yoshikuni Matsunaga

Tetsuhiko Takahashi

Etsuji Yamamoto

Toshihiko Shimizu

Masao Kondo

Satoshi Sakurai

Isao Yoshida

Kenta Seki

Masatoshi Morikawa

Toru Fujioka

Osamu Kagaya

Kenji Sekine

Mineo Katsueda

Yuri Kusakari

Tomio Furuya

Nobuhiro Matsudaira

Koichi Matsushita

Kageyoshi Katakura

Yoshiki Murakami

Hiroyuki Takeuchi

Tetsuaki Adachi

Wasao Takasugi

Hiroyuki Itagaki

Masao Hotta

Takayuki Nabeshima

Ryuichi Suzuki

Ryuuichi Shinomura

A reduction is achieved in the primary-side input impedance of a transformer (voltage transformer) as an output matching circuit without involving a reduction in Q-factor. An RF power amplifier includes transistors, and a transformer as the output matching circuit. The transformer has a primary coil and a secondary coil which are magnetically coupled to each other. To the input terminals of the transistors, respective input signals are supplied. The primary coil is coupled to each of the output terminals of the transistors. From the secondary coil, an output signal is generated. The primary coil includes a first coil and a second coil which are coupled in parallel between the respective output terminals of the transistors, and each magnetically coupled to the secondary coil. By the parallel coupling of the first and second coils of the primary coil, the input impedance of the primary coil is reduced.

RF power amplifier

Power amplifier circuits which constitute an RF power module used for a digital device capable of handling high frequency signals in two frequency bands are disposed over the same IC chip. The power amplifier circuits are disposed around the IC chip, and a secondary circuit is disposed between the power amplifier circuits. Thus, the power amplifier circuits are provided within the same IC chip to enable a size reduction. Further, the distance between the power amplifier circuits is ensured even if the power amplifier circuits are provided within the same IC chip. It is therefore possible to suppress the coupling between the power amplifier circuits and restrain crosstalk between the power amplifier circuits.

Semiconductor device

A multistage high frequency power amplifier-circuit device has a plurality of semiconductor amplification elements connected in a cascade. The circuit device is provided with a bias control circuit used to control the bias voltage or bias current of the output semiconductor amplification element in each stage so as to reduce the variation of the output power with respect to the power control signal voltage in an area around the threshold voltage of the semiconductor amplification elements. This realizes a high frequency power amplifier circuit device provided with excellent controllability of the output power and high efficiency at the time of low power output realized with use of such a control voltage as a power control signal.

High frequency power amplifier circuit device

A multistage high frequency power amplifier circuit device has a plurality of semiconductor amplification elements connected in a cascade. The circuit device is provided with a bias control circuit used to control the bias voltage or bias current of the output semiconductor amplification element in each stage so as to reduce the variation of the output power with respect to the power control signal voltage in an area around the threshold voltage of the semiconductor amplification elements. This realizes a high frequency power amplifier circuit device provided with excellent controllability of the output power and high efficiency at the time of low power output realized with use of such a control voltage as a power control signal.

In a mobile telephone apparatus corresponding to dual-band provided with an RF power module to operate in two kinds of different frequencies, a common harmonics control circuit is provided to the output circuit of such RF power module to realize higher efficiency in view of controlling respective harmonics power for both band frequencies. Moreover, a means for selectively setting the bias is also provided so that the maximum efficiency can be attained depending on the output power required with respective communication systems with the bias control signal output from the CPU of the control unit interlocking with selection of frequency of the mobile telephone apparatus body.

Mobile telephone apparatus

A radio frequency power amplifier module for a dual-band type mobile communication apparatus that can transmit and receive a first frequency f and second frequency f (f f ). It includes a drive stage amplifier having the gain peaks at f and f with a matching circuit and a radio frequency power output circuit including a radio frequency power output transistor. The output circuit has a transmission line connected to the drain end of the output transistor, a parallel resonance circuit connected in series to the transmission line to resonate at harmonics of a frequency twice the frequency f , a series resonance circuit provided between one end of the resonance circuit and the ground to resonate at harmonics of a frequency twice the frequency f and an output matching circuit provided in series to the other end of the parallel resonance circuit for matching with f and f

High-frequency power amplifier module

A high frequency power amplifier module is provided for improving output controllability. A wireless communication apparatus incorporates a high frequency power amplifier module in a multi-stage configuration including a plurality of cascaded MOSFETS. The power amplifier module comprises a bias circuit for generating a gate voltage in response to a power control voltage (vapc) generated based on a power control signal of the wireless communication apparatus. The gate voltage has a bias pattern which presents smaller fluctuations in output power in response to a control voltage (Vapc) in a region near a threshold voltage (Vth) of the MOSFETs in respective amplification stages. In this way, the controllability for the output power is improved. More specifically, the power amplifier module has a gate bias circuit for generating the gate voltage (Vg) which follows a gate voltage pattern. The gate voltage (Vg) supplied to a control terminal in response to the control voltage (Vapc) largely changes in a region where the gate voltage (Vg) is lower than the threshold voltage (Vth) of the respective MOSFETs, and slightly changes near the threshold voltage (Vth). Also, the gate voltage (Vg) presents desired characteristics from the vicinity of the threshold voltage (Vth) to a high Vapc voltage region.

High frequency power amplifying module and wireless communication apparatus

Growing community of inventors

Niiza, Japan

Yoshikuni Matsunaga