QUADRATURE MODULATION APPARATUS, METHOD, PROGRAM, AND RECORDING MEDIUM

摘要

PROBLEM TO BE SOLVED: To provide technology of calibrating a quadrature demodulator without applying quadrature demodulation to an RF signal obtained by quadrature modulation.

SOLUTION: A quadrature modulation apparatus is provided with: an in-phase multiplier 14I for mixing an in-phase local signal Lo having a prescribed local frequency with an in-phase calibration user signal resulting from adding an in-phase calibration signal having a sinusoidal wave voltage outputted from an in-phase calibration signal output unit 32I to an in-phase user signal (I signal) to output an in-phase conversion signal; a quadrature multiplier 14Q for mixing a quadrature local signal Lo resulting from shifting the phase of the in-phase local signal by 90 degrees with a quadrature calibration user signal resulting from adding a quadrature user signal (Q signal) to a quadrature calibration signal obtained by shifting the phase of the in-phase calibration signal outputted from a quadrature calibration signal output unit 32Q by 90 degrees to output a quadrature conversion signal; an adder 18 for summing up the in-phase conversion signal and the quadrature conversion signal; a power detector 56 for measuring the output voltage of the adder 18; and an error determining section 62 for determining the error of the quadrature modulation on the basis of a result of the measurement by the power detector 56.

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