Panasonic Corporation

Nippon Electric Glass Co., Ltd.

Matsushita Electric Industrial Co., Ltd.

Hiroshi Komori

Hiroki Yamazaki

Kaoru Ishida

Ryo Kitamura

Mikihiro Shimada

Takeaki Watanabe

Masatoshi Igarashi

Noriaki Saito

Masahiro Maeda

Masatoshi Kamitani

Shinkichi Miwa

Masahiro Tomamoto

Akio Yokoyama

Takahiro Shima

Yukihiro Omoto

Yoshinari Kato

Masato Seki

Yoichi Morita

Atsushi Yoshimoto

Masatake Irie

Yutaka Ohtani

Provided is a compensation circuit capable of improving compensation precision for manufacturing variations. The compensation circuit includes a manufacturing variation detection circuit which detects manufacturing variation of a transistor based on a first voltage output from an output terminal of the transistor having an input terminal applied with a substantially constant first current to temperature or based on a second current output from an output terminal of the transistor having an input terminal applied with a substantially constant second voltage to temperature, and a voltage generation circuit which generates a supply voltage supplied to an electric circuit based on the manufacturing variation. The first current corresponds to the substantially constant second voltage to temperature, and the first voltage corresponds to the substantially constant second current to temperature.

Compensation circuit and compensation method

A current output circuit includes a current mirror circuit that has first and second transistors in each of which a source is connected to a reference voltage, and that outputs a current which is proportional to a drain current of the first transistor, from a drain of the second transistor; a switch that turns ON/OFF the current output of the current mirror circuit; a third transistor in which a gate is connected to a gate of the second transistor; and a bias circuit that applies a first voltage to a drain of the third transistor. The bias circuit switches the first voltage to two different voltages in synchronization with opening/closing of the switch.

Current output circuit and wireless communication apparatus

An injection locked frequency divider includes a ring oscillator, an input terminal, an output terminal and a control voltage terminal. The ring oscillator has a three-stage cascade connection of a first amplification circuit including an N-channel MOS type transistor and P-channel MOS type transistors, a second amplification circuit configured in the same manner as the first amplification circuit and a third amplification circuit configured likewise. A high frequency signal is input to a gate terminal of each P-channel MOS type transistor. A predetermined DC control voltage is supplied to a gate terminal of each P-channel MOS type transistor.

Injection locked oscillator

Provided is a method of producing a tempered glass sheet, comprising applying tempering treatment to a glass sheet by increasing the content of SiOin terms of mass in a surface region of a glass sheet through application of thermal treatment to the glass sheet to 1.03 or more times that in an interior region positioned at a depth of 1 &#x3bc;m from a surface of the glass sheet.

Method of producing tempered glass sheet

Provided is a transmitter apparatus including: a signal conversion section for, in polar modulation, converting input data into an amplitude-component signal and a phase-component signal, and in quadrature modulation, converting input data into an in-phase component signal and a quadrature component signal; a carrier wave generation section for outputting a carrier wave; a mixer section for, in quadrature modulation, generating a quadrature modulation signal; a regulator for, in polar modulation, outputting a supply voltage control signal; and a power amplifier for, in polar modulation, amplifying the supply voltage control signal and superimposing the resultant signal onto the carrier wave, thereby generating a transmission signal, wherein in polar modulation, the carrier wave generation section outputs the carrier wave modulated with respect to phase component, and in quadrature modulation, the carrier wave generation section outputs the carrier wave that is yet to be modulated.

Transmitter apparatus

A transmission circuit according to the present invention includes: an amplitude signal driving section () that generates a control voltage based on an amplitude signal in a high-output mode, and generates a control voltage at a predetermined level and a bias current based on the amplitude signal in a low-output mode; a variable gain adjustment section () that adjusts a power level of the phase signal; and a power amplifier () which amplitude-modulates the phase signal having the adjusted power level on the basis of the control voltage, in the high-output mode, and to a power supply terminal of which the control voltage is supplied and which amplitude-modulates the phase signal having the adjusted power level on the basis of the bias current, in the low-output mode. In a specific region in a low-output region and close to a high-output region, the variable gain adjustment section () adjusts the power level of the phase signal to a predetermined upper-limit level, and the amplitude signal driving section () adjusts a gain of the power amplifier () to obtain a desired output power level.

Transmission circuit

A transmission circuit () according to the present invention includes an RF-IC (), an EM-IC (), and a power amplifier (). The EM-IC () includes a DC-DC converter (), a transistor (), a low-dropout regulator (), and a regulator output selector switch (). After an elapse of a predetermined time from a time when an operation mode of the transmission circuit has switched from a polar modulation mode to a quadrature modulation mode to a time when a power supply voltage for the quadrature modulation mode output from the DC-DC converter () stabilizes at a desired value, the regulator output selector switch () switches a connection destination of a gate of the transistor () to a fixed potential, and outputs as a control voltage the power supply voltage for the quadrature modulation mode output from the DC-DC converter ().

A transmitter circuit is provided which is capable of reducing modulation distortion even when an output power of a power amplifying sectionis low. A signal generation sectiongenerates an amplitude signal and a phase signal. A regulatoroutputs a current based on the amplitude signal. A phase modulation sectionphase-modulates the phase signal, and outputs a phase-modulated signal. The power amplifying sectionreceives the current which is based on the amplitude signal and supplied as a bias current from the regulator, and amplifies the phase-modulated signal by using the supplied current. Further, to the power amplifying section, a predetermined DC voltage is supplied as a collector voltage.

Transmitter circuit and communication apparatus

A constant-voltage circuit includes: first and second field-effect transistors; a first node connected to the drains of the first and second field-effect transistors; a second node connected to the gates of the first and second field-effect transistors; a bipolar transistor whose collector is connected to the second node; a resistor connected to the source of the second field-effect transistor and the collector of the bipolar transistor; and a bias circuit that is connected to the source of the second field-effect transistor and supplies a bias voltage to the base of the bipolar transistor, wherein a power supply is connected to the first node and a constant voltage is outputted from the source of the first field-effect transistor.

Constant-voltage circuit

Provided is a glass substrate, which has a substrate size of 1,100 mm&#xd7;1,250 mm or more, and a transmittance at a wavelength of 500 to 800 nm and at a route length of 50 mm of 80% or more.

Glass substrate

A frequency mixer device is provided with a mixer circuit having an input cell that amplifies an input signal and a switching cell that mixes the amplified input signal with a switching signal and outputs a multiplied signal, and a DC offset compensator that detects the input level of the input signal and outputs a compensation signal based on that detection signal, the compensation signal being supplied to the mixer circuit so as to compensate a DC offset included in the multiplied signal. The compensation signal that the DC offset compensator outputs is added to the output signal of the input cell so as to compensate the DC offset. Low frequency noise included in the compensation signal is converted to a frequency near that of the switching signal, and does not range over the desired waveband of the mixer output.

Frequency mixer device and method for compensating DC offset

A direct conversion receiver includes a mixer for converting an RF signal into a baseband signal, a dynamic DC offset compensator for compensating for a dynamic DC offset caused by the effect of second order nonlinear distortion of the mixer on an interfering wave that enters the input terminals of the mixer, and a static DC offset compensator for compensating for a static DC offset caused by self-mixing of a local signal and a leakage component of the local signal that appears at the input terminals of the mixer. The static DC offset compensation starts at a time tafter a DC offset compensation operation has started. The static DC offset compensation is finished at the next time t, and then the dynamic DC offset compensation starts. The dynamic DC offset compensation is finished at the next time t. With this configuration, only a change in DC offset due to the dynamic DC offset is compensated after compensating for the static DC offset component. The dynamic DC offset compensator does not have an element for storing the magnitude of the static DC offset.

Direct conversion receiver with DC offset compensation

A division ratio of a first frequency divider that generates a local signal and a division ratio of a second frequency divider that generates a RF interfering signal are different, and a first frequency synthesizer that generates the local signal and a second frequency synthesizer that generates the RF interfering signal employ an identical reference signal. The second frequency synthesizer that generates the RF interfering signal is not provided with a frequency switching function.

DC offset calibration system

In a configuration wherein an output signal from a differential oscillator is input into a differential buffer amplifier, an operating current for the differential oscillator including a resonator, which has a node at the midpoint of an inductor, and a pair of field-effect transistors for oscillation and an operating current for the differential buffer amplifier including a pair of bipolar transistors for amplification are made common. In order to obtain the common operating current, the current from the pair of bipolar transistors for amplification is fed from the midpoint of the inductor into the pair of field-effect transistors for oscillation.

Differential oscillator circuit

A high pass filter is disposed to an output part of a gain control amplifier. A gain control signal change detector detects a change of a gain control signal from the gain control amplifier. Upon detection of a change of the gain control signal, a counter and a clock generator generate a cancel pulse which has a certain width, and using the cancel pulse, a first switch cuts an AC signal which is fed to the gain control amplifier. Further, using the same cancel pulse, a second switch reduces the time constant of the high pass filter. Through this operation, a transient response of a DC offset is eliminated.

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Otsu, Japan

Hiroshi Komori