Panasonic Corporation

Matsushita Electric Industrial Co., Ltd.

Takayuki Tsukizawa

Kenji Miyanaga

Noriaki Saito

Koji Takinami

Hisashi Adachi

Shunsuke Hirano

Koichiro Tanaka

Hiroyuki Yoshikawa

Masakatsu Maeda

Yukio Hiraoka

Atsushi Ohara

In a wireless communication device, baseband variable gain amplifiers amplify a baseband signal. Mixers convert the amplified baseband signal into a high-frequency transmission signal. Hybrid variable gain amplifiers amplify an in-phase local signal and an orthogonal local signal which are input to the mixers. The level detection controller changes respective gains of the baseband variable gain amplifiers and the hybrid variable gain amplifiers, in response to power of the high-frequency transmission signal.

Wireless communication device

A wireless communication device of the present disclosure has: a transmitter having a plurality of transmission circuit branches; a receiver having a plurality of reception circuit branches; a transmission phase switch; a reception phase switch; and a phase/transmission-reception controller, and has a beam-forming function. When phase switching is performed during a plurality of training packets for setting directivity, the phase/transmission-reception controller controls the transmission phase switch and the reception phase switch by setting a same phase for each of m (m being an integer of 2 or more) number of continuous training packets. In addition, the phase/transmission-reception controller performs control such that the transmission of the transmitter and the reception of the receiver are set to an OFF state in at least one or more training packets from the beginning of the m number of continuous training packets.

Wireless communication device, transmitter, receiver, and beam-forming control method

A variable gain amplifier amplifies a baseband signal. A quadrature modulator quadrature-modulates the amplified baseband signal to generate a high-frequency signal. A power amplifier amplifies the generated high-frequency signal. An antenna transmits the amplified high-frequency signal. A detector detects the amplified high-frequency signal. A first nonvolatile memory stores the desired transmission power of the high-frequency signal to be transmitted from the antenna. A controller adjusts the gain of the variable gain amplifier depending on the output of the detector and the transmission power stored in the first nonvolatile memory.

Wireless communication apparatus and transmission power control method

A signal-generating circuit includes a voltage-controlled oscillator that generates an oscillated signal; a first frequency divider that generates a first divided signal by dividing the oscillated signal; a second frequency divider that generates a second divided signal by dividing the divided signal; a phase comparator that receives as input the second divided signal and a reference signal and outputs two signals corresponding to a phase difference therebetween; a loop filter that extracts a low frequency signal between the two signals to be output to the voltage-controlled oscillator; a third frequency divider that generates a third divided signal by dividing the first divided signal; a first frequency converter that generates a first frequency converted signal by multiplying the oscillated signal by the third divided signal; and a first multiplier that generates a multiplied signal by multiplying the first frequency converted signal by a first multiplication number.

Signal-generating circuit and wireless communication device

A wireless communication device includes a BBIC for performing baseband signal processing, an RFIC for performing radio-frequency signal processing, and a quartz resonator. The RFIC has a storage unit which stores an adjustment value for adjustment of a clock frequency that is based on an oscillation frequency of the quartz resonator, and outputs the adjustment value when its resetting active state is canceled; a frequency adjusting unit for adjusting the clock frequency according to the adjustment value; and an RF signal processing unit which operates based on the clock signal and performs the radio-frequency signal processing.

Wireless communication device and activation method of the wireless communication device

A wireless communication device includes a digital modulation signal generator that generates digital modulation signals, a DAC that converts digital output of the digital modulation signal generator into analog signals, a modulator that generates amplified quadrature modulation signals by exerting quadrature modulation and amplification on the analog signals, an antenna that radiates the amplified quadrature modulation signals, a power detector that outputs power detected signals obtained from power detection of the amplified quadrature modulation signals, a controller that adjusts gain of the modulator by using the power detected signals and a desired power value, a thermometer that measures ambient temperatures at a plurality of burst transmission periods, and a high-power prevention circuit that readjusts the gain of the modulator for a present burst transmission period.

A modulation section including a feedback circuit configured to conduct feedback control of an output signal from a voltage controlled oscillator based on an inputted modulation signal, and a feed-forward circuit configured to calibrate the modulation signal and outputting the calibrated modulation signal to the voltage controlled oscillator; a signal output section configured to output, to the modulation section, a predetermined reference signal instead of the modulation signal when a calibration is conducted; and a gain correction section configured to, in a state where the feedback circuit is forming an open loop, calculate a frequency transition amount of the reference signal outputted by the voltage controlled oscillator, and correct a gain used for calibrating the modulation signal at the feed-forward circuit based on the calculated frequency transition amount.

Two-point modulation device using voltage controlled oscillator, and calibration method

Provided is a voltage-controlled oscillator that can hold an oscillation frequency at a desired value when an oscillation frequency changes due to the temperature, without narrowing a variable range of the oscillation frequency, and a PLL circuit, an FLL circuit, and a wireless communication device, which use the voltage-controlled oscillator. A control voltage Vt is applied to a connection point Y between variable capacitorsandincluded in a variable capacitance circuit. A control signal Fseis applied to a switching elementincluded in a capacitance switching circuit. A power-supply voltage Vdd is applied by a control sectionto a connection point X between inductorsandincluded in an inductor circuit. A voltage value of the power-supply voltage Vdd is controlled such that the oscillation frequency of the local oscillation signal is held at a constant regardless of a temperature change.

PLL/FLL with voltage controlled oscillator

A voltage controlled oscillator includes first and second variable capacitance circuits 120 and 130, and first and second capacitance switch circuits 140 and 150. A control voltage Vt is fixedly applied to the first variable capacitance circuit 120, and control signals Fsel2 and Fsel3 are fixedly applied to the first and second capacitance switch circuits 140 and 150, respectively. When both of the control signals Fsel2 and Fsel3 are at a low level, the control signal Fsel1 is applied to the second variable capacitance circuit 130. When the control signals Fsel2 and Fsel3 are both not at the low level, the control voltage Vt is applied to the second variable capacitance circuit 130. As a result of this control, a high-frequency variable range is divided into two variable ranges, one based on upper frequencies and the other based on lower frequencies. This enables suppression of a frequency sensitivity without narrowing the high-frequency variable range.

Voltage controlled oscillator, and PLL circuit and wireless communication device each using the same

A voltage controlled oscillator includes an inductor circuit, C-coupling type variable capacitance circuits, a direct-coupling type variable capacitance circuit, and a negative resistance circuit, which are connected in parallel, and a reference voltage generating section that generates two reference voltages. A control voltage for feedback control of an oscillation frequency is applied to back gate terminals of variable capacitance elements of the variable capacitance circuits. The reference voltages are applied to gate terminals of the variable capacitance elements of the C-coupling type variable capacitance circuits, respectively.

Voltage controlled oscillator, and PLL circuit and radio communication device each including the same

Provided is a PLL oscillation circuit that can reduce the variability of modulation sensitivity of a VCOand obtain a desired output amplitude quickly with high precision. An amplitude detectordetects an output amplitude of the VCO. An amplitude controllercontrols a current value of a variable current sourceso as to have an output amplitude of the VCOdetected by the amplitude detectorto be a desired amplitude. A LPFis connected between the amplitude controllerand the variable current source. A switchconnects or disconnects the LPFbetween the amplitude controllerand the variable current source. The amplitude controlleris connected to the variable current sourcethrough either the LPFor the switching switch

PLL oscillation circuit, polar transmitting circuit, and communication device

A voltage controlled oscillator has a reference voltage generation section for generating a plurality of reference voltage based on a power supply voltage. Reference voltages VrefVrefand Vrefare inputted to variable capacitance circuits A, B, and C, respectively. Reference voltages VrefVrefand Vrefeach has a fixed value, and a difference between the first reference voltage Vrefand the second reference voltage Vrefand a difference between the second reference voltage Vrefand the third reference voltage Vrefrepresent values different from each other. A control voltage Vt for feedback-controlling an oscillation frequency is inputted to each of the other of the terminals of the variable capacitance element of each of the n variable capacitance circuits such that the control voltage Vt having the same value is inputted to the each of the other of the terminals.

Voltage controlled oscillator, and PLL circuit and radio communication apparatus using the same

A voltage controlled oscillator including an inductor circuit including inductors, a variable capacitance circuithaving variable capacitance elementschanging a capacitance according to a voltage difference between two terminals thereof and having capacitive elementscutting a DC component, a negative resistance circuit including cross-coupled oscillating transistors, and a time-switched level shift circuitfor shifting a reference voltage to two or more levels in a predetermined period. A connection point A of the variable capacitance elements is supplied with a control voltage Vt controlling an oscillation frequency, and connection points B, C of the variable capacitance elements and the capacitive elements are supplied with a reference voltage Vref output from the time-switched level shift circuitvia resistors

Voltage controlled oscillator, and PLL circuit and wireless communication apparatus using the same

The present invention provides a differential voltage control oscillator including: a parallel resonance circuit in which an inductor circuit, a variable capacitance circuit, and a radio-frequency switching circuit are connected in parallel together; and a negative resistance circuit connected in parallel with the parallel resonance circuit. The radio-frequency switching circuit includes: a first switching element; a first capacitive element; a second switching element; a second capacitive element; a control voltage terminal for supplying a common control voltage to the first and second switching control terminals, the control voltage terminal being connected to a virtual ground point for a differential signal generated in the parallel resonance circuit; a first radio-frequency signal reduction section connected between the control voltage terminal and the first switching element; and a second radio-frequency signal reduction section connected between the control voltage terminal and the second switching element.

Differential voltage control oscillator including radio-frequency switching circuits

A voltage controlled oscillator comprises a parallel resonance circuit including an inductor circuit, a variable capacitance circuit, and a high-frequency switch circuit, a negative resistance circuit and a frequency control section, and a frequency tuning sensitivity control section. The frequency control section shifts a band of an oscillation frequency by controlling ON/OFF of a switching element included in the high-frequency switch circuit. The frequency tuning sensitivity control section adjusts a change rate of a total capacitance of the variable capacitance circuit with respect to a control voltage, depending on a band to be used. The frequency tuning sensitivity control section is connected to a virtual ground point of a differential signal.

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Osaka, Japan

Takayuki Tsukizawa