Hitachi, Ltd.

Renesas Technology Corp.

Ttpcom Limited

Other

Renesas Electronics Corporation

Hitachi Medical Corporation

Nippon Telegraph and Telephone Public Corporation

Hitachi Denshi Kabushiki Kaisha

Director-general of the Agency of Industrial Science and Technology

Hitachi Electronics, Ltd.

Tipcom Limited

Masao Hotta

Kenji Maio

Toshihiko Shimizu

Yoshito Nejime

Satoshi Tanaka

Taizo Yamawaki

Kazuo Watanabe

Masumi Kasahara

Kumiko Takikawa

Toyohiko Hongo

Norio Yokozawa

Koichi A Ono

Hiroshi Ikeda

Yuji Hatano

Hirotsugu Kojima

Takafumi Kikuchi

Hiromi Nagaishi

Shinichi Hayashi

Mitsuru Hiraki

Masaru Kokubo

Isao Yoshida

Hideki Sawaguchi

Koichi Seki

Kouki Noguchi

Naoki Satoh

Tetsuaki Adachi

Masatoshi Morikawa

Yoshikuni Matsunaga

Shigeru Watanabe

Toru Fujioka

Yoshikazu Miyamoto

Akinori Shibayama

Hisashi Kado

Mitsunobu Iwabuchi

Masanori Otsuka

Yoshimitsu Oshima

Atsushi Moritani

Keiko Makie

Yasuyuki Murakami

Kenzi Maio

Masahiro Higuchi

A transceiver suitable for larger scale of integration employs direct conversion reception for reducing the number of filters. Also, the number of VCOs is reduced by utilizing dividers to supply a receiver and a transmitter with locally oscillated signals at an RF band. Dividers each having a fixed division ratio are used for generating locally oscillated signals for the receiver, while a divider having a switchable division ratio are used for generating the locally oscillated signal for the transmitter. In addition, a variable gain amplifier for baseband signal is provided with a DC offset voltage detector and a DC offset canceling circuit for supporting high speed data communications to accomplish fast cancellation of a DC offset by eliminating intervention of a filter within a feedback loop for offset cancellation.

Mobile communication apparatus

Mobile communication apparatus including dividers in transmitter and receiver

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

Making use of a digital acoustic signal processing apparatus arranged by employing memory device for storing a digital acoustic signal, acoustic frequency feature enhancing device for enhancing an acoustic frequency feature, and low-speed sound reproducing device for changing a speed of the stored voice to reproduce this voice as a low speed into a hearing aid and an appliance with an acoustic output, a hearing function difficulty due to an age is aided in utilization of audio output appliances such as a hearing aid, television receiver, and a telephone receiver. After the voice has been stored in the memory device, a process for enhancing the frequency characteristic in order to fit the frequency characteristic to the individual hearing characteristic and the voice reproducing environment is carried out and thereafter represented to the user. The user can repeatedly listen the voice stored in the memory device with employment of control device for controlling the voice reproducing operation. Furthermore, since a process for expanding a time scale during a sound reproducing operation is carried out, the voice can be represented at the low speed. Since the voice whose frequency characteristic has been enhanced can be represented at the low speed in order that either an individual hearing ability, or an apparatus is fitted to a using environment, hearing articulation can be improved with respect to such a hearing, the frequency resolution and the time resolution are simultaneously deteriorated.

Digital voice processing apparatus providing frequency characteristic processing and/or time scale expansion

A bus driving system includes n bus wires having data signal wires and control signal wires, (n-1) switching circuits constituting driver circuits at a transmitting end, a precharge circuitry for precharging (n-2) bus wires and (n-1)-th bus wire with a control circuit for redistributing wire capacitances of transmission lines formed by the bus wires, and a predischarge circuitry for predischarging n-th bus wire. The switching circuits control conduction and non-conduction between (n-2) bus wires, (n-1)-th bus wire and n-th bus wire, wherein the (n-2) switching circuits respond to (n-2) bit signals and a control signal, while the (n-1)-th switching circuit responds to the control signal. The signal from the transmitting end is detected by a detection circuit at a receiving end via the transmission lines.

Bus driving system and integrated circuit device using the same

Digital acoustic signal processing apparatus

In a mobile wireless communication end device having an electric power source including a cell, and a signal processing part and a transmitting-receiving part, to which electric power is applied from the electric power source, operation is performed in operation mode selected previously by the user when voltage of the electric power source is dropped. The signal processing part and the transmitting-receiving part have a normal operation mode operating at normal electric power and a low power operation mode operating at electric power lower than the normal operation mode. The mobile wireless communication end device includes operation mode setting apparatus for previously setting the operation mode of the device, observing apparatus for observing the voltage of the cell of the electric power source and generating a low power operation request signal when the voltage becomes a prescribed value or less, and apparatus for changing the signal processing part and the transmitting-receiving part to low power operation mode, when the low power operation mode is set by the operation mode setting means and the low power operation request signal is generated by the observing apparatus.

Mobile communication end device with low power operation mode

A signal processing apparatus for converting an analog signal to a digital signal and processing the digital signal. In particular, a digital filter for performing processing at high speed is implemented by using an integrated circuit of low power consumption. The signal processing apparatus includes a circuit for comparing an input analog signal with each voltage of a plurality of analog reference voltages and generating a thermometer code Tc depending upon the analog input signal, a decoder for detecting a change point of the thermometer code Tc, and a plurality of memory circuits having output signal lines of the decoder as word selection lines. The product of an input signal value corresponding to each word selection line and a predetermined filter coefficient is stored in the corresponding word of the memory circuits. The memories are used as look-up tables.

Signal processing apparatus having A/D conversion function

A multichannel weak magnetic field measuring system for neuromagnetic diagnosis is provided having a plurality of dc-SQUID magnetometers. Bias current setting circuits are provided for detecting an even harmonic component of the output across the terminals of the corresponding SQUID and automatically adjusting a DC bias current to the SQUID. Accordingly, the level of the component becomes a predetermined value. Circuitry is also included for equalizing the magnetic flux detection sensitivities of these dc-SQUID magnetometers. Abnormal operation detecting circuits are also provided for producing abnormal operation detected outputs when the level of the corresponding even harmonic component is smaller than a certain threshold value.

Weak magnetic field measuring system using dc-SQUID magnetometer with

An integrated circuit including a plurality of circuits having the same input impedance, arranged at regular intervals, and applied with a signal from a single signal source, is disclosed in which the input impedance is substantially capacitive, the characteristic impedance of a signal line connected to the signal source for sending the signal to the circuits is given by Z.sub.0 .sqroot.L/C, where L indicates the inductance of the signal line per one circuit, and C indicates the combined capacitance of the parasitic capacitance of the signal line per one circuit and the input capacitance of each circuit, the signal line is terminated by a circuit element having impedance equal to the characteristic impedance Z.sub.0, and the signal source has output impedance equal to the characteristic impedance Z.sub.0.

Integrated circuit compensation for losses in signal lines due to

A reference analog signal is supplied to an analog-to-digital converter via a sample-and-hold circuit and an amplifier so as to obtain digital data corresponding to the reference analog signal. The obtained digital data corresponding to the reference analog signal is compared with predetermined reference data. The gain and the offset voltage of the amplifier is corrected so as to make the difference between the digital data corresponding to the reference analog signal and the reference data smaller than a predetermined allowance on the basis of the comparison result.

Analog-to-digital conversion method and system with correction of analog

A radiation detection circuit integrates output currents of a plurality of X-ray CT scanner radiation detectors, which are combinations of scintillators and photodiodes, during a short period to convert them to charge information in order to collect data for reproducing a tomogram. A current amplifier is connected to the output terminal of the photo-diode, and an output current of the current amplifier is charged in an integration capacitor. In this manner, the radiation detection circuit enables reduction of the measurement period.

Radiation detection circuit having a signal integrating capacitor, and a

Disclosed is a parallel analog-to-digital converter in which a plurality of comparators are divided into a plurality of groups each consisting of a predetermined number of comparators, and outputs of at least these comparators belonging to the same group are added in an analog or digital fashion. Whether or not the result of addition of the outputs of the comparators exceeds a predetermined threshold level is decided in an analog or digital fashion so as to determine high-order and low-order bits of a digital output signal of the converter on the basis of the result of decision.

High-speed analog-to-digital converter

Growing community of inventors

Hanno, Japan

Masao Hotta