Abstract: A radio communication device has an analog control loop unit to generate an analog control signal that adjusts a phase of a voltage control oscillation signal, a digital control loop unit to generate a digital control signal having a frequency determined by a frequency of a reference signal and a predetermined frequency setting code signal and a phase opposite to a phase of the analog control signal, a voltage controlled oscillator to generate the voltage control oscillation signal, a data slicer to generate a digital signal including the reception signal, an automatic offset controller to generate a correction signal in response to an error between a frequency of the reception signal and a frequency of the voltage control oscillation signal, and a setting code adjuster to adjust the frequency setting code signal, wherein gain of the digital control loop unit is higher than gain of the analog control loop unit.

Abstract: An oscillator has an oscillator which comprises a first variable capacitor to adjust capacitance based on a first signal and a second variable capacitor to adjust capacitance, generates an oscillation signal having a frequency in accordance with the capacitance of the first variable capacitor and the second variable capacitor, an integer phase detector to detect an integer phase of the oscillation signal, a fractional phase detector to detect a fractional phase of the oscillation signal, a phase error generator to generate a fourth signal indicating a phase error of the oscillation signal, a first filter to extract the first signal in a predetermined frequency band, included in the fourth signal, and to output the first signal, and a second filter to extract the second signal in a predetermined frequency band, included in the fourth signal, and to output the second signal.

Abstract: A receiver has an oscillator to output an oscillation signal, a receiver to perform reception processing of a reception signal, a phase frequency detector to output a first signal in response to a phase and a frequency of the oscillation signal so as to generate a second signal indicating a reference phase, a differentiator to generate a third signal being a difference between the first signal and the second signal, an oscillator controller to generate a fourth signal for controlling a phase and a frequency of the oscillator, a phase initializer to output an initialization signal for synchronizing a phase of the second signal with a phase of the first signal, a trigger signal generator to output a trigger signal indicating timing with which the phase initializer outputs the initialization signal, and a power supply controller to control whether to supply a power supply voltage.

Abstract: A time to digital converter has a counter to measure the number of cycles of a first signal, a first phase difference detector to generate a phase difference signal having a pulse width corresponding to a phase difference, a first capacitor to be charged with an electric charge, a second capacitor including capacitance N times the capacitance of the first capacitor, the N being a real number larger than 1, a comparator to compare a charge voltage of the first capacitor and a charge voltage of the second capacitor, a first charge controller to continue to charge the second capacitor until the comparator detects that the charge voltage of the second capacitor has reached the charge voltage of the first capacitor or more, and a first phase difference arithmetic unit to operate the phase difference between the first signal and the second signal.

Abstract: A wireless communication device has an analog control loop circuitry that generates an analog control signal to adjust a phase of a voltage controlled oscillation signal, in accordance with a phase of a reception signal, a digital control loop circuitry that generates a digital control signal having a frequency determined by a frequency of a reference signal and a predetermined frequency setting code signal and having a phase opposite to a phase of the analog control signal, a voltage controlled oscillator that generates the voltage controlled oscillation signal, on the basis of the analog control signal and the digital control signal, and a data slicer that generates a digital signal obtained by digital demodulation of the reception signal, on the basis of a comparison result of the digital control signal and a predetermined threshold value.

Abstract: A radio communication device has an analog control loop unit to generate an analog control signal that adjusts a phase of a voltage control oscillation signal, a digital control loop unit to generate a digital control signal having a frequency determined by a frequency of a reference signal and a predetermined frequency setting code signal and a phase opposite to a phase of the analog control signal, a voltage controlled oscillator to generate the voltage control oscillation signal, a data slicer to generate a digital signal including the reception signal, an automatic offset controller to generate a correction signal in response to an error between a frequency of the reception signal and a frequency of the voltage control oscillation signal, and a setting code adjuster to adjust the frequency setting code signal, wherein gain of the digital control loop unit is higher than gain of the analog control loop unit.

Abstract: An amplifier circuit has a sample-and-hold circuit to sample and hold an input signal, an amplifier which comprises an input terminal inputted with the input signal held by the sample-and-hold circuit and an output terminal outputting an amplification signal obtained by amplifying the input signal inputted, a feedback capacitor to be connected between the input terminal and output terminal of the amplifier, a successive approximation circuit to perform successive approximation operation to correct the amplification signal based on a voltage of the input terminal of the amplifier, the successive approximation operation being performed a predetermined number of cycles, and a control circuit to control the successive approximation circuit based on an amplification error included in the amplification signal.

Abstract: A wireless communication device has an analog control loop circuitry that generates an analog control signal to adjust a phase of a voltage controlled oscillation signal, in accordance with a phase of a reception signal, a digital control loop circuitry that generates a digital control signal having a frequency determined by a frequency of a reference signal and a predetermined frequency setting code signal and having a phase opposite to a phase of the analog control signal, a voltage controlled oscillator that generates the voltage controlled oscillation signal, on the basis of the analog control signal and the digital control signal, and a data slicer that generates a digital signal obtained by digital demodulation of the reception signal, on the basis of a comparison result of the digital control signal and a predetermined threshold value.

Abstract: A radio communication device has a local oscillator to generate a local signal, a first mixer to mix a binary continuous phase frequency shift keying signal and the local signal so as to generate a baseband signal, a first filter to remove an unnecessary frequency component included in the baseband signal, a delay device to delay an output signal of the first filter by one symbol, and a wave detector to demodulate the continuous phase frequency shift keying signal, wherein a modulation index m of the continuous phase frequency shift keying signal is a value expressed by m=n+k where 0<n<1 is satisfied and k is an integer of 0 or more, and a frequency of the local signal is a frequency shifted by a frequency corresponding to 0 or 1 of the continuous phase frequency shift keying signal.

Abstract: An integrator according to an embodiment includes first and second nodes, first to fifth switches, first and second main integration capacitors, and a first subsidiary integration capacitor. The first (second, third, fourth, fifth) switch has one end connected to a first (third, first, fourth, first) node and the other end connected to a third (second, fourth, second, fifth) node. The first main integration capacitor has one end connected to the third node and the other end connected to a standard voltage line. The second main integration capacitor has one end connected to the fourth node and the other end connected to the standard voltage line. The first subsidiary integration capacitor that has one end connected to the fifth node and the other end connected to the standard voltage line.

Abstract: A wireless communication apparatus has an analog control loop circuitry to generate an analog control signal which adjusts a phase of a voltage-controlled oscillation signal, an integrator to integrate the analog control signal, a phase adjuster to adjust a phase of the voltage-controlled oscillation signal, a digital control loop circuitry, in a first mode, to match a frequency of the voltage-controlled oscillation signal to a frequency of the received signal based on an output signal of the phase adjuster, and in a second mode, to generate a digital control signal which is opposite in phase to the analog control signal and has a frequency, a voltage-controlled oscillator to generate the voltage-controlled oscillation signal based on the analog and digital control signals, and a signal switch to supply the analog control signal to the integrator in the first mode and to the voltage-controlled oscillator in the second mode.

Abstract: An amplifier circuit has a sample-and-hold circuit to sample and hold an input signal, an amplifier which comprises an input terminal inputted with the input signal held by the sample-and-hold circuit and an output terminal outputting an amplification signal obtained by amplifying the input signal inputted, a feedback capacitor to be connected between the input terminal and output terminal of the amplifier, a successive approximation circuit to perform successive approximation operation to correct the amplification signal based on a voltage of the input terminal of the amplifier, the successive approximation operation being performed a predetermined number of cycles, and a control circuit to control the successive approximation circuit based on an amplification error included in the amplification signal.

Abstract: An A/D converter has an analog input terminal, an analog output terminal, a digital output terminal, a first resistance comprising one end connected to the analog input terminal or a reference voltage line and another end connected to a first node, a second resistance comprising one end connected to the first node and another end connected to the analog output terminal, an operational amplifier comprising a first input terminal connected to the first node, a second input terminal connected to the reference voltage line or the analog input terminal, and an output terminal connected to the analog output terminal, a quantizer comprising an input terminal connected to the analog input terminal and an output terminal connected to the digital output terminal, and a DA converter comprising an input terminal connected to the digital output terminal and an output terminal connected to the first node.

Abstract: An A/D converter circuit has an amplifier circuit to amplify an input signal and output a first amplification signal and a second amplification signal, the second amplification signal having an amplification error smaller than that in the first amplification signal, a first sampling circuit to sample the first amplification signal, a first A/D converter to perform A/D conversion on the first amplification signal sampled by the first sampling circuit and output a first digital signal, a second sampling circuit to sample the second amplification signal, a D/A converter to perform D/A conversion on the first digital signal and output a first analog signal, a subtracter to subtract the first analog signal from the second amplification signal sampled by the second sampling circuit and output a second analog signal, and a second A/D converter to perform A/D conversion on the second analog signal and output a second digital signal.

Abstract: An A/D converter circuit has an amplifier circuit to amplify an input signal and output a first amplification signal and a second amplification signal, the second amplification signal having an amplification error smaller than that in the first amplification signal, a first sampling circuit to sample the first amplification signal, a first A/D converter to perform A/D conversion on the first amplification signal sampled by the first sampling circuit and output a first digital signal, a second sampling circuit to sample the second amplification signal, a D/A converter to perform D/A conversion on the first digital signal and output a first analog signal, a subtracter to subtract the first analog signal from the second amplification signal sampled by the second sampling circuit and output a second analog signal, and a second A/D converter to perform A/D conversion on the second analog signal and output a second digital signal.

Abstract: According to an embodiment, an amplifier which amplifies a first signal to output a second signal includes the following elements. The comparator compares the first signal with a third signal to output a fourth signal. The delay circuit delays a fifth signal by a delay time to generate a sixth signal. The first capacitor is connected between a voltage source and a first node that provides the third signal. The second capacitor is connected between the first node and a second node that provides the second signal. The first switch is connected between the second node and a constant current source, and is controlled by the fourth signal and the fifth signal. The second switch is connected between the first node and the second node, and is controlled by the fifth signal and the sixth signal.

Abstract: An A/D converter has an analog input terminal, an analog output terminal, a digital output terminal, a first resistance comprising one end connected to the analog input terminal or a reference voltage line and another end connected to a first node, a second resistance comprising one end connected to the first node and another end connected to the analog output terminal, an operational amplifier comprising a first input terminal connected to the first node, a second input terminal connected to the reference voltage line or the analog input terminal, and an output terminal connected to the analog output terminal, a quantizer comprising an input terminal connected to the analog input terminal and an output terminal connected to the digital output terminal, and a DA converter comprising an input terminal connected to the digital output terminal and an output terminal connected to the first node.

Abstract: An amplifier circuit has a sampling circuit to comprise a sampling capacitor which samples an input voltage and a plurality of switches, a quantizer to quantize an output voltage of the sampling circuit, a DA converter to output an analog signal depending on a quantization signal by the quantizer, and a feedback capacitor to feed the analog signal back to the output voltage of the sampling circuit.

Abstract: According to an embodiment, an analog-to-digital converter includes a detection circuit, a first conversion circuit, a second comparator, a delay control circuit, a control circuit. A detection circuit detects a differential time signal corresponding to a delay time by using a comparison signal and a delay comparison signal. A first conversion circuit generates a differential voltage by performing time-to-voltage conversion on the differential time signal. A second comparator generates a digital delay determination signal by comparing the differential voltage and an adjustment target voltage. A delay control circuit generates a delay control signal controlling the delay time in accordance with a delay determination signal. A control circuit generates a control signal by using the delay comparison signal in an analog-to-digital conversion period.

Abstract: A current detection circuit according to one embodiment includes a low-pass filter, a voltage-to-current converter circuit, and a comparator. The low-pass filter has a first terminal connected to a signal input terminal to which a signal current is input. The voltage-to-current converter circuit has a first terminal connected to a second terminal of the low-pass filter and has a second terminal connected to the signal input terminal. The comparator has a first input terminal and a second input terminal and outputs a signal according to a difference between a signal input through the first input terminal and a signal input through the second input terminal, the first input terminal being connected to the second terminal of the low-pass filter, and the second input terminal being connected to the second terminal of the voltage-to-current converter circuit.