An electronic circuit includes a circuit to receive an analog input signal responsive to an analog oscillating signal and to generate an analog output signal, AD converters to perform AD-conversion with respect to the analog oscillating signal, the analog input signal, and the analog output signal to generate a digital oscillating signal, a digital input signal, and a digital output signal, at least one first adjustor to adjust a phase of the digital oscillating signal through the Hilbert transform, a second adjustor to adjust a phase of the digital input signal through the Hilbert transform, a third adjustor to adjust a phase of the digital output signal through the Hilbert transform, a first mixer circuit to multiply the output of the first adjustor and the output of the second adjustor, and a second mixer circuit to multiply the output of the first adjustor and the output of the third adjustor.