Patent application number | Description | Published |
20080238495 | FREQUENCY SYNTHESIZER AND WIRELESS COMMUNICATION DEVICE UTILIZING THE SAME - A frequency synthesizer includes a voltage-controlled oscillator to output an oscillation signal of a oscillating frequency in correspondence with a oscillation controlling voltage that is input to the oscillator, a first frequency-divider to subject the oscillation signal to frequency-division and output a first frequency signal, a second frequency-divider to subject the first frequency signal to frequency-division and output a second frequency signal, a controlling voltage generator to generate the oscillation controlling voltage corresponding to a phase difference between a reference clock signal and the second frequency signal, a frequency detector to detect a frequency difference between the second frequency signal and the reference clock signal, and a controller which controls a free-running frequency of the first frequency divider to minimize the frequency difference. | 10-02-2008 |
20090067555 | FILTER CIRCUIT, RECEIVER USING THE SAME AND FILTERING METHOD - A filter circuit includes a sampler which samples an input signal to generate a first analog signal, an analog-to-digital converter which converts the first analog signal into a first digital signal, a digital filter which extracts a signal component out of a desired band from the first digital signal to generate a second digital signal, a digital-to-analog converter which converts the second digital signal into a second analog signal, a delay device which imparts a signal delay to the first analog signal to supply a third analog signal, the signal delay being equal to a delay time of the second analog signal relative to the first analog signal, and a subtracter which subtracts the second analog signal from the third analog signal to generate an output signal. | 03-12-2009 |
20090075619 | MIXER CIRCUIT AND RADIO COMMUNICATION DEVICE USING THE SAME - A mixer circuit includes a voltage-to-current converter which converts a positive phase input voltage signal and a reversed phase input voltage signal input to a first input terminal and a second input terminal into a positive phase current signal and a reversed phase current signal, a switching circuit switches over the positive phase current signal and the reversed phase current signal according to a positive phase local signal and a reversed phase local signal, and generates a positive phase output current signal and a reversed phase output current signal, and an impedance element connected between the first common terminal and the second common terminal, having a relatively high impedance to a differential-mode signal between the positive phase current signal and the reversed phase current signal, and having a relatively low impedance to a common-mode signal between the positive phase current signal and the reversed phase current signal. | 03-19-2009 |
20090302958 | DIGITALLY CONTROLLED OSCILLATOR AND PHASE LOCKED LOOP CIRCUIT USING THE DIGITALLY CONTROLLED OSCILLATOR - A digitally controlled oscillator includes a differential inductor including a positive terminal which outputs a positive-phase oscillation signal, a negative terminal which outputs a negative-phase oscillation signal, and a center tap, and including a first contact point in an arbitrary position between the positive terminal and the center tap, and a second contact point in a position corresponding to the first contact point between the negative terminal and the center tap, a first variable capacitor bank connected between the positive terminal and the negative terminal and including a plurality of first variable capacitors which switch capacitance between two values according to a first digital control code, and a second variable capacitor bank connected between the first contact point and the second contact point and including a plurality of second variable capacitors which switch capacitance between two values according to a second digital control code. | 12-10-2009 |
20100073222 | FMWC SIGNAL GENERATOR AND RADAR APPARATUS USING FMCW SIGNAL GENERATOR - An FMCW signal generator includes a frequency divider to divide the FMCW signal at a preset dividing ratio, a reference signal generator to periodically generate a reference signal at a second time interval not less than a loop time constant set for a PLL, a frequency of the reference signal being discretely swept within a range of fc±Δf (fc is a center frequency, and Δf is a frequency sweep width) at a first time interval not more than the loop time constant, a comparison unit to compare the frequency divided signal with the reference signal to generate a comparison result signal corresponding to a phase difference between the frequency divided signal and the reference signal, a loop filter to filter the comparison result signal to generate a control voltage signal, and a VCO to have an oscillation frequency thereof controlled by the control voltage signal. | 03-25-2010 |
20100164633 | PLL CIRCUIT AND RADIO COMMUNICATION APPARATUS - A PLL circuit includes: a voltage-controlled oscillator including: a first oscillating portion configured to generate first differential signals; and a second oscillating portion configured to generate second differential signals with a phase difference of 90 degrees from the first differential signals; a phase detector configured to compare phases of third differential signals based on the first and second differential signals with a phase of a reference signal; and a loop filter configured to generate a control voltage for controlling the voltage-controlled oscillator based on a result of the comparison in the phase detector. | 07-01-2010 |
20100203851 | WIRELESS TRANSMISSION DEVICE AND WIRELESS TRANSMISSION METHOD - A wireless transmission device includes an adding/subtracting unit configured to subtract a second signal and a third signal from a first signal to generate the second signal; a modulating unit configured to modulate the second signal to generate a fourth signal; a demodulating unit configured to demodulate the fourth signal to generate the third signal; and a transmitting unit configured to transmit the fourth signal. | 08-12-2010 |
20100225397 | AMPLIFIER AND RADIO - An amplifier includes: a substrate; first to fourth amplifying units arranged on the substrate and each having first and second terminals, and each amplifying first and second signals to generate first and second amplified signals; a first inductive line arranged on the substrate, connecting the first terminal of the first amplifying unit and the first terminal of the second amplifying unit, and having a linear portion and a bending portion; a second inductive line arranged on the substrate, connecting the second terminal of the second amplifying unit and the first terminal of the third amplifying unit, and having a linear portion and a bending portion; a third inductive line arranged on the substrate, connecting the second terminal of the third amplifying unit and the first terminal of the fourth amplifying unit, and having a linear portion and a bending portion; a fourth inductive line arranged on the substrate, connecting the second terminal of the fourth amplifying unit and the second terminal of the first amplifying unit, and having a linear portion and a bending portion; and a fifth inductive line which establishes magnetic field coupling with the first to fourth inductive lines, and has third and fourth terminals, combines the plurality of the first amplified signals amplified to output the first combined signal from the third terminal, and combines the plurality of the second amplified signals to output the second combined signal from the fourth terminal. | 09-09-2010 |
20110116558 | WIRELESS TRANSMISSION APPARATUS USING CARTESIAN LOOP - In one embodiment, a wireless transmission apparatus is disclosed. The apparatus includes a generator unit, an amplitude adjuster unit, a phase adjuster unit, and a setting unit. The generator unit generates an amplitude control signal that minimizes an amplitude difference and a phase control signal that minimizes a phase difference in a state in which a power is set during an OFF period of a switch. The amplitude adjuster unit adjusts an amplitude of a feedback RF signal according to the amplitude control signal during an ON period of the switch. The phase adjuster unit adjusts a phase of a local signal according to the phase control signal during the ON period. The setting unit sets, for a Cartesian loop, a first loop gain when the switch is OFF, and a second loop gain higher than the first loop gain when the switch is turned from OFF to ON. | 05-19-2011 |