Sony Corporation

Nippon Telegraph and Telephone Corporation

Sony Semiconductor Solutions Corporation

Shinichi Tanabe

Hideo Morohashi

Kazuhiro Fujimura

Hideaki Sato

Takashi Usui

Nobuyuki Ishikawa

Kenji Komori

Hiroshi Higuchi

Masataka Wakamatsu

Fumio Ishikawa

Hisaaki Narahara

Kazuyuki Saijo

Noriyuki Watanabe

Stuart Francis Glynn

Dariush Zadeh

The present technique pertains to a signal processing apparatus, a signal processing method, and a receiving apparatus that enable gain control to be appropriately performed on various interfering signals. An amplifier controls a gain according to a count value to amplify a signal, and a comparator compares the signal outputted by the amplifier with the count value. An accumulator counts the count value according to an output from the comparator. The present technique can be applied to, for example, a receiving apparatus that receives an RF signal for a television broadcast.

Signal processing apparatus, signal processing method, and receiving apparatus

A third semiconductor layer () including a third nitride semiconductor is provided between an electrode () and a second semiconductor layer () including a second nitride semiconductor. The band gap of the second nitride semiconductor is set such that the carrier movement between a first semiconductor layer () and the third semiconductor layer () via the second semiconductor layer () is rate-determined by a diffusion process. The thickness of the second semiconductor layer () is set such that the carrier movement between the first semiconductor layer () and the third semiconductor layer () via the second semiconductor layer () is rate-determined by the diffusion process. The carrier movement between the first semiconductor layer () and the third semiconductor layer () via the second semiconductor layer () is rate-determined by a field emission process.

Semiconductor device and method of manufacturing the same

A digital baseband signal for radio frequency transmission is processed prior to performing digital-to-analog conversion. The digital baseband signal is filtered. The number of bits of the digital baseband signal is reduced to minimise the size of the digital-to-analog converter. By performing some of the bit reduction before filtering, the size of the filter circuit is reduced whilst still meeting relevant performance parameters.

Bit reduction in a transmitter

An automatic gain control circuit able to perform high speed and correct level acquisition, able to prevent occurrence of error, and able to prevent a crash of the system. An amplification gain controller outputs a gain control signal to an automatic gain control amplifier to amplify the received signal with maximum value when receiving a burst detection trigger signal. A second gain control signal based on the detected reception signal power is calculated when receiving a first burst synchronization detection signal; and this second gain control signal is output to the automatic gain control amplifier. A received digital signal is amplified with the second gain and integrated to find the reception signal power, from which a third gain control signal is calculated and outputted to the automatic gain control amplifier to amplify the received signal with this third gain.

Automatic gain control circuit and method thereof and demodulation apparatus using the same

A gain control circuit comprises a variable gain circuit having a predetermined gain control range and a control voltage supply circuit for supplying an internal control voltage to the variable gain circuit as a gain control signal. In this gain control circuit, the control voltage supply circuit generates the internal control voltage in response to an external control voltage so as to compensate the linearity of the variable gain circuit to the extent of the external control voltage where the variable gain circuit loses linearity. This gain control circuit is applied to an AGC circuit of the transmitting stage in a CDMA-type mobile phone.

Gain control circuit, and a radio communication apparatus using the same

The present invention provides systems and methods related to a variable gain amplifier. The variable gain amplifier includes a first differential amplifier, a second differential amplifier, a combining circuit, and a current control circuit. The first differential amplifier circuit and the second differential amplifier circuit share a common input signal and have different amplification degrees. Each of the first and second differential amplifier circuits includes a first transistor and a second transistor that form a differential pair. The first transistor and the second transistor of each differential amplifier circuit have bases that are supplied with the input signal, and collectors that output signals to the combining circuit. The current control circuit changes a ratio between a bias current of the first differential amplifier circuit and a bias current of said second differential amplifier circuit based on a gain control signal.

Variable gain amplifier

A grounded emitter amplifier and a radio communication device using the same in which a bias voltage is generated in order to adjust an emitter current of a transistor in a grounded emitter amplification circuit so that the emitter current does not receive an influence of variations in several parameters of the transistor such as a current amplification factor hfe.

Grounded emitter amplifier and a radio communication device using the same

An RF modulator comprising an FM modulator supplied with an audio signal, and AM modulator supplied with the FM modulator output and a video signal, an oscillator for generating a sound subcarrier signal, and an oscillator for generating a main carrier signal. Each of the oscillators consists of a VCO with a PLL circuit, and the entire components are composed of a single IC chip so as to be formed into a compact miniature structure. A modified RF modulator includes a PLL circuit for varying the oscillation frequency of a VCO by a variable frequency divider, and a modulation circuit supplied with a modulating signal and the oscillation output of the VCO. The division ratio (integer) of the variable frequency divider is continuously varied, and the reference frequency of a reference oscillator is set to be less than a predetermined channel interval frequency, thereby reducing the frequency error in the modulated signal output.

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Kanagawa, Japan

Shinichi Tanabe