Abstract: An FMCW signal generation circuit includes: an oscillator configured to oscillate in an oscillation frequency that is variable in accordance with a control signal being input thereto and output an FMCW signal having the oscillation frequency; a phase detector configured to detect a phase of the FMCW signal; a first differentiator configured to obtain a frequency by differentiating the phase detected by the phase detector; a second differentiator configured to obtain a frequency variation rate by differentiating the frequency obtained by the first differentiator; a subtractor configured to calculate an error between a set frequency variation rate that is set at a given value and the frequency variation rate obtained by the second differentiator; and an integrator configured to generate the control signal for controlling the oscillation frequency of the oscillator by integrating the error calculated by the subtractor.

Abstract: According to an aspect of the invention, an oscillating circuit includes: a first MOS transistor having a first drain terminal and a first source terminal; a load element connected to the first drain terminal; and an oscillator connected to the first source terminal and outputs a fundamental signal and a harmonic signal, wherein the harmonic signal is amplified so that the amplified harmonic signal is output from the first drain terminal.

Abstract: 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±?f (fc is a center frequency, and ?f 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.

Abstract: A frequency converter includes a voltage-current converter circuit which generates a positive-phase input current signal and a negative-phase input current signal, a switching circuit which switches between the positive-phase input current signal and the negative-phase input current signal according to a positive-phase local oscillator signal and a negative-phase local oscillator signal to generate a positive-phase output current signal and a negative-phase output current signal, an amplifier circuit which current-voltage converts and amplifies the positive-phase output current signal and negative-phase output current signal to generate a positive-phase output voltage signal and a negative-phase output voltage signal, and a plurality of CR circuits which are inserted at least either between the voltage-current converter circuit and the switching circuit or between the switching circuit and the amplifier circuit and each of which includes at least one capacitor through which high-frequency components pass and

Abstract: 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.

Abstract: 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.

Abstract: Disclosed is a frequency converter including: a passive type analog multiplier configured to output a multiplication result in a current; a buffer outputting a buffering current by buffering the current of the multiplication result; and a current-voltage converter current-voltage converting the buffering current. Alternately, disclosed is a frequency converter including: a passive type analog multiplier configured to output a multiplication result in a current; a buffer outputting a buffering current by buffering the current of the multiplication result; and an integrator integrating the buffering current to output a voltage.