Transmitter, signal generation device, calibration method, and signal generation method

摘要

It is intended to provide a transmitter capable of correcting signal distortion with high accuracy. Provided are a test signal generator; a frequency characteristics corrector for correcting an amplitude characteristic and a phase characteristic of a test signal; a modulator; an envelope detector; a frequency characteristics calculator for calculating frequency characteristics of an envelope signal; and a coefficients calculator for calculating, on the basis of the frequency characteristics, correction coefficients to be used for correcting the amplitude characteristic and the phase characteristic of the test signal. The test signal generator generates a test signal in which signal loci in each of at least two pairs of quadrants of first to fourth quadrants of the IQ plane are not symmetrical with each other.

主权项

1. A transmitter comprising:
a test signal generator which, in operation, generates a test signal; a frequency characteristics corrector which, in operation, corrects an amplitude characteristic and a phase characteristic of the test signal generated by the test signal generator; a modulator which, in operation, modulates a corrected signal produced by the frequency characteristics corrector; an envelope detector which, in operation, detects an envelope of a modulated signal produced by the modulator; a frequency characteristics calculator which, in operation, calculates frequency characteristics of an envelope signal detected by the envelope detector; and a coefficients calculator which, in operation, calculates, on the basis of the frequency characteristics calculated by the frequency characteristics calculator, correction coefficients to be used by the frequency characteristics corrector to correct the amplitude characteristic and the phase characteristic of the test signal, wherein the test signal generator, in operation, generates the test signal in which signal loci in at least two of quadrants of first to fourth quadrants of the IQ plane are not symmetrical with each other, and sweeps frequencies in a prescribed frequency range of the test signal; wherein the frequency characteristics calculator, in operation, extracts a set of complex data respectively from a set of the envelope signals, which respectively correspond to angular frequency components of the test signal; and wherein the coefficients calculator, in operation, calculates the correction coefficients on the basis of the extracted set of complex data.