Matsushita Electric Industrial Co., Ltd.

Panasonic Corporation

Mamoru Arayashiki

Yoshihiro Hara

Masaharu Udagawa

Shunsuke Hirano

Norihide Kinugasa

Akio Yokoyama

Taichi Ikedo

Hisashi Takahashi

Michiyo Yamamoto

Maki Nakamura

A two-point frequency modulation apparatus is proposed whereby the spectrum of transmission waves is kept within the spectrum mask. Voltage is supplied to the control voltage terminal of VCOin accordance with modulation data via noise shaperthat has operating characteristics of attenuating more noise at higher frequencies. As a result, by virtue of the working of noise shaper, the signal level outputted from the PLL circuit combining the modulation signal and the quantization noise decreases in proportion to the distance form the central frequency, so that two-point frequency modulation apparatusis made possible whereby the spectrum of an RF modulation signal is kept within the spectrum mask.

Two-point frequency modulation apparatus

A transmission device having a preferable power efficiency and a wide control range of transmission output power. A pre-stage side of a high-frequency power amplifier changes an amplitude of a high-frequency phase modulation signal according to a base band amplitude modulation signal and a gain control signal. A variable gain amplifier changes the amplitude of the high-frequency phase modulation signal according to the base band amplitude modulation signal and the gain control signal, so that the base band amplitude modulation signal is supplied to an amplifier via a linear-log converter.

Transmission device and radio communication device

Polar modulation transmission apparatus capable of suppressing power loss of a battery supply line to a high-frequency power amplifier regardless of whether transmission power is high or low is provided. Operation control section () performing control in such a manner that a battery voltage (S) converted as a result of operation of a DC/DC converter () is applied to amplitude signal amplifying section () or halting operation of the DC/DC converter () in such a manner that battery voltage (S) is applied directly from the battery () based on a transmission power control signal (S). As a result, when transmission power is low, power loss at the amplitude signal amplifying section () is suppressed by DC/DC converter (), unnecessary operation of DC/DC converter () is halted when transmission power is high, and power loss can be suppressed regardless of whether transmission power is high or low.

Polar modulation transmission apparatus and wireless communication apparatus

A transmitting apparatus includes a polar signal producing circuit which produces signals corresponding to the amplitude and the phase of a transmitting modulated wave from an input signal and multiplies the amplitude signal by the phase signal by a multiplying circuit to amplitude modulate a phase-modulated wave to produce a transmitting modulated wave and radiates this transmitting modulated wave as radio wave from an antenna. An amplitude/phase detecting circuit detects an amplitude signal and a phase signal from the input of the multiplying circuit and the input of a phase-modulated signal producing circuit. A delay difference computing circuit computes a correlation function between the amplitude signal produced by the polar signal producing circuit and the amplitude signal detected by the amplitude/phase detecting circuit and a correlation function between the phase signal produced by the polar signal producing means and the phase signal detected by the amplitude/phase detecting means, and computes a delay difference between the amplitude signal and the phase signal from maximum values of the respective correlation functions. Then, a timing adjusting circuit adjusts the delay time between the amplitude signal and the phase signal on the base of the computed delay difference.

Transmitter apparatus and method using polar modulation with signal timing adjustment

Either linear operating mode or saturation operating mode is set as the operating mode of a high-frequency power amplifier on the basis of an operating mode set signal. The gain of a variable gain amplifier provided in front of the high-frequency power amplifier and values of output voltage and bias current supplied from a supply voltage/bias current control circuit to the high-frequency power amplifier are switched. The gain of the variable gain amplifier in the saturation operating mode is formed so as to be higher by a predetermined value than that in the linear operating mode. Accordingly, the high-frequency power amplifier operates in the designated operating mode, so that the output transmission power range can be widened.

Transmission device, transmission output control method, and radio communications device

A transmitting apparatusoperates a high-frequency power amplifieras a nonlinear amplifier in a first mode, and operates high-frequency power amplifieras a linear amplifier in a second mode. When high-frequency power amplifieris operated as a nonlinear amplifier, the input level of high-frequency power amplifieris varied by a variable gain amplifierin accordance with the average output power of a transmit signal. Transmitting apparatusis also provided with a compensation tablefor reducing error in high-frequency power amplifiermode switching operations.

Transmitting apparatus and radio communication apparatus

Linear transmission modulation apparatushas high frequency amplifierthat amplifies the high frequency phase modulation signal of a high frequency signal and power source voltage controllerthat amplifies the baseband amplitude modulation signal of the high frequency signal. Power source voltage controllerhas delta sigma amplifierthat performs delta sigma amplifying of the baseband amplitude modulation signal and generates a delta sigma amplification signal and delta amplifierthat performs delta amplifying of the baseband amplitude modulation signal and generates a delta amplification signal. In response to a modulation mode switching control signal that indicates as to whether or not the amplitude modulation signal fluctuates, one of delta sigma amplifierand delta amplifieroperates and sends out an output.

Transmission modulation apparatus

A transmitter and method to output a stable output signal having low distortion by adjusting a delay time of an amplitude signal path and a phase signal path. In an amplitude phase extracting part, amplitude data and phase data are extracted from a transmit data signal and outputted. The amplitude of the amplitude data is modulated in an amplitude modulating part and an amplitude modulating signal is outputted; the phase of the phase data is modulated and a phase modulating signal is outputted. In a non-linear amplifying part, the phase modulating signal is multiplied by the amplitude modulating signal to output an RF signal with a prescribed gain amplified. A delay part provided in a pre-stage of the amplitude modulating part and a delay part provided in a pre-stage of the phase modulating part, respectively, adjusts the delay time of an amplitude signal path and a phase signal path.

Transmission device and delay time adjustment method thereof

To tune the center frequency of a gm-C filter, which is a bandpass filter with a narrow bandwidth, to a target frequency, only while the filter is being tuned, the original circuit configuration of the filter is replaced with an alternative configuration that realizes a high signal-to-noise ratio. A characteristic tuner generates and inputs an impulse signal, pulse signal or step signal to the filter being tuned and thereby detects and adjusts the center frequency of the filter. And the tuning result is stored on a nonvolatile memory for future reuse. When the filter is operated, the characteristic tuner stops operating to cut down the power dissipation.

Growing community of inventors

Yokohama, Japan

Mamoru Arayashiki