Sony Corporation

Sony Ericsson Mobile Communications Japan, Inc.

Kotaro Takagi

Satoshi Yokoya

Nishiki Mizusawa

Kunio Sato

Nobutaka Takao

Kazunori Imazaki

Provided is a router including a network interface that communicates with a network, a first communication interface that communicates with a mobile communication interface of a wireless communication device through a mobile communication control station, a second communication interface that communicates with a wireless LAN interface of the wireless communication device through a wireless LAN control station, and a conversion unit that converts an origin address of one of data to the network received from the mobile communication interface and data to the network received from the wireless LAN interface into an origin address of another one of the data.

Wireless communication device, router, wireless communication system, and wireless communication method

A variable capacitance circuit capable of switching on and off a variable capacitance function, includes variable capacitance means formed such that variable capacitance elements whose capacitance values change according to a voltage value of a supplied capacitance control voltage are connected so as to be paired and a plurality pairs of variable capacitance elements are connected in parallel forming multiple stages; bias voltage generation means for generating bias voltages of different voltage values based on a constant voltage from a constant voltage source; and an on-off switch for the variable capacitance function, in which the variable capacitance function of the variable capacitance means is turned on by supplying the bias voltage to the variable capacitance element of each stage of the variable capacitance means and turned off by grounding the bias voltage of each voltage value.

Variable capacitance circuit having on/off switch for variable capacitance function, and voltage controlled oscillator using the variable capacitance circuit

There are provided, as a low noise amplifier () a low noise amplifier () with a low gain and a low noise amplifier () with a high gain, selectively operable under control of a bias current, and an output from the low noise amplifier () and a quadrature demodulator () are connected with a serial capacitance () and also an output from the low noise amplifier () and the quadrature demodulator () are serially connected. A control section () controls a reception circuit so that the low noise amplifier () operates when a reception signal level is high and the low noise amplifier () operates when the reception signal level is low. When the low noise amplifier () operates, a DC bias current thereof is made flow separately from a DC bias current of the quadrature demodulator (), and, when the low noise amplifier () operates, a DC bias current thereof is shared with the quadrature demodulator.

Receiver circuit and radio communication terminal apparatus

A voltage-controlled oscillator comprising a resonant circuit and MOS transistors which constitute a negative resistance circuit of a differential structure. The resonant circuit consists of an inductance element and a MOS variable capacitance element connected in parallel therewith. The MOS variable capacitance element is divided into plural pairs connected in parallel with each other. A voltage division circuit generates staircase different-step DC bias voltages to be applied respectively to the gates of the plural divided MOS transistors. The divided MOS variable capacitance elements have a common terminal to which a common control voltage is applied. The resonant circuit is capable of reducing a load on the control voltage generator and improving the characteristics of the voltage-controlled oscillator.

Resonant circuit and a voltage-controlled oscillator

The object of this invention is to demodulate received signals having different received signal frequencies with the simple circuit configuration. With the present invention, the fixed frequency signals are generated at the fixed PLL unit, and simultaneously, the standard frequency signals corresponding respectively to GSM/DCS received RF signals are generated at the channel PLL unitAnd using the image removal mixerjointly to received RF signals, local oscillation signals having local oscillation frequencies equal to the received signal frequencies of the received RF signals respectively are formed from the fixed frequency signals and the standard frequency signals for receiving. And since the quadrature demodulatorsanddemodulate the received RF signals using corresponding local oscillation signals respectively, the circuit configuration can be simplified by sharing the image removal mixerThereby, receiving signals having different received signal frequencies can be demodulated with the simple circuit configuration.

Radio signal receiving apparatus and demodulating circuit

A digital communication apparatus in which a QPSK signal is received and frequency-converted to an intermediate frequency signal, the intermediate frequency signal is subjected to A/D conversion and separation into an I-component and a Q-component to obtain I-component and Q-component digital data, and the original digital data is obtained from the I-component and Q-component digital data. The digital commumication apparatus has an A/D converter circuit for performing the above-mentioned A/D conversion, a level control circuit for controlling the level of a signal supplied to the A/D converter circuit to a predetermined value, and a disturbance signal level detection circuit for detecting the disturbance signal level contained in the received signal.

Digital communication apparatus having level controller with a disturbance detection unit

A receiving apparatus is disclosed which can cope with the fluctuation of input level of RF signal appropriately and has a first amplifier means wherein the amplifying and the attenuating of input signal are selectively performed and for processing the signal in a communication band handled by this apparatus, and a second amplifier means for gain-variably amplifying a signal, which is a signal converted from the output of the first amplification means,into the intermediate frequency signal or base band signal, the gain of the second amplifier means being set based on the detection of output level of the second amplifier means, and the selection of the amplification or attenuation in the first amplifier means, (,) being performed based on the detection level of output from the first amplifier means.

Receiving apparatus

A receiving apparatus for receiving digital broadcasting of a first frequency band and frequency band has a local oscillation circuit for generating a first local oscillation signal, and a frequency conversion circuit for frequency-converting the first local oscillation signal to generate a second local oscillation signal. The received signal of the first frequency band is up-converted to a first intermediate frequency signal using one of the of first and second local oscillation signals, and the received signal of the frequency band is down-converted to the first intermediate frequency signal using the other of the first and second local oscillation signals. Further, the receiving apparatus has another local oscillation circuit for oscillating a local oscillation frequency used for frequency conversion of the first intermediate frequency signal to a second intermediate frequency signal, an A/D converter for A/D converting the second intermediate frequency signal, and an orthogonal demodulation circuit for extracting I-component data and Q-component data from the A/D converted signal and for digital-converting the data.

Receiving apparatus for digital broadcasting

A portable telephone which solves problems conventionally associated with using a portable telephone together with a hands-free accessory is disclosed. When the portable telephone is being used on its own and a microphone arm thereof is in a home position, the portable telephone can be put in a waiting state wherein it can receive incoming calls. When the portable telephone is being used on its own and the microphone arm is in a pulled-out position, telephone conversations can be had using a microphone and a speaker built into the portable telephone. When the portable telephone is connected to a hands-free accessory and the microphone arm is in its home position, conversations can be had in a hands-free mode using a microphone and a speaker connected to the hands-free accessory. When the portable telephone is connected to a hands-free accessory and the microphone arm is in its pulled-out position, conversations can be had in a normal mode using the microphone and the speaker built into the portable telephone even though the portable telephone is connected to the hands-free accessory. As a result, no special key for mode changeover between the hands-free mode and the normal mode need be provided either on the portable telephone side or on the hands-free accessory side, nor is it necessary to perform a two-step key pressing operation to effect mode changeover.

Telephone handset for hands-free use in an auto mobile

A radio telephone apparatus for transmitting and receiving information signals as electrical waves includes a main body section towards one end of which a speaker unit is enclosed. A battery casing accommodating a battery which is adapted for supplying power to the main body section is detachably mounted on the other end of the main body section to reduce the size and the thickness of the apparatus. A ringer device is enclosed within the battery casing so that the acoustic sound emitted by the ringer is prevented from reaching the user's ear which is in the vicinity of the speaker unit. The microphone for the radiotelephone apparatus in also enclosed within the battery casing.

Radio telephone apparatus with microphone mounted in battery case

A charge pump circuit for charging a capacitor in response to a phase difference between first and second input signals comprises a constant current source for providing a first constant current; a constant current sink for absorbing a second constant current; a circuit for substantially equalizing the magnitudes of the first and second constant currents; and a switching circuit for providing the first constant current and the second constant current flowing in opposed directions to the capacitor through an output terminal of the charge pump circuit in response to the phase difference between the first and second input signals to produce a voltage level across the capacitor corresponding to the phase difference. In a phase locked loop system employing such a charge pump circuit, a phase comparator produces a phase difference signal for controlling the provision of the first and second constant currents by the switching circuit to the capacitor. The capacitor acts as a loop filter supplying the voltage thereacross as a control voltage to a voltage controlled oscillator of the phase locked loop system.

Phase locked loop system having an oscillator providing a phase

Charge pump circuit

A filter apparatus comprised of a multi-layer printed circuit board has a shielded filter with input and output terminals protruding from the circuit board, when the filter is mounted on the printed circuit board. Two insulating substrates form the printed circuit board, and a connective conductive pattern is formed on an inner surface of one of the substrates that faces the other substrate. Conductive layers are formed on respective outer surfaces of the substrate opposing the connection conductive pattern, wherein at least one of the input and output terminals of the filter is connected to the connective conductive pattern and the conductive layers are grounded, thereby shielding the connective conductive pattern.

Filter apparatus

A television receiver can be used both to generate a picture and sound from a broadcast video signal or to generate just a picture from a locally produced video signal, such as one provided by a video camera. A muting apparatus suppresses the sound generated from the broadcast video signal while the television receiver is used as a monitor for the locally produced video signal. The muting apparatus comprises a level shifter that raises the level of the broadcast video signal. A switching means provides to the picture tube of the television receiver either the broadcast video signal or, if the video camera is plugged into the receiver, the locally produced video signal. The level of the signal supplied to the picture tube is sensed; if it is below the predetermined level a muting means connects the audio component of the broadcast video signal to ground to prevent sound from being generated while the receiver is used as a monitor.

Growing community of inventors

Kanagawa, Japan

Kotaro Takagi