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

A transmitter comprising:

• a test signal generator configured to generate a first test signal and a second test signal;
• a signal corrector configured to correct IQ imbalance of a test signal generated by the test signal generator;
• a modulator configured to modulate a corrected signal produced by the signal corrector through the correction;
• an envelope detector configured to detect an envelope of a modulated signal produced by the modulator through the modulation;
• and
• a correction coefficients processor configured to calculate, on the basis of the envelope detected by the envelope detector, correction coefficients to be used by the signal corrector to correct the IQ imbalance,
• wherein the test signal generator generates a first test signal and a second test signal according to a detectable range of the envelope detector;
• and
• wherein the correction coefficients processor calculates a reference phase of the test signal on the basis of a first envelope corresponding to the first test signal, calculates a measurement phase of the test signal on the basis of a second envelope corresponding to the second test signal, and calculates correction coefficients on the basis of the measurement phase and the reference phase.

A signal generation device comprising:

• a test signal generator configured to generate a test signal;
• a frequency characteristics corrector configured to correct an amplitude characteristic and a phase characteristic of the test signal generated by the test signal generator;
• a frequency characteristics calculator configured to calculate frequency characteristics of an envelope signal of a modulated signal produced by modulating a corrected signal that is produced by the frequency characteristics corrector through the correction;
• and
• a coefficients calculator configured to calculate, 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 generates a 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.

A signal generation device comprising:

• a test signal generator configured to generate a first test signal and a second test signal;
• a signal corrector configured to correct IQ imbalance of a test signal generated by the test signal generator;
• and
• a correction coefficients processor configured to calculate, on the basis of an envelope of a modulated signal produced by modulating a corrected signal that is produced by the signal corrector through the correction,
• wherein the test signal generator generates a first test signal and a second test signal according to a detectable range of an envelope detector for detecting the envelope;
• and
• wherein the correction coefficients processor calculates a reference phase of the test signal on the basis of a first envelope corresponding to the first test signal, calculates a measurement phase of the test signal on the basis of a second envelope corresponding to the second test signal, and calculates correction coefficients on the basis of the measurement phase and the reference phase.

A calibration method comprising:

• a test signal generation step of generating a test signal;
• a frequency characteristics correction step of correcting an amplitude characteristic and a phase characteristic of the generated test signal;
• a frequency characteristics calculation step of calculating frequency characteristics of an envelope signal of a modulated signal produced by modulating a corrected signal produced through the correction;
• and
• a coefficients calculation step of calculating, on the basis of the calculated frequency characteristics, correction coefficients to be used for correcting the amplitude characteristic and the phase characteristic of the test signal,
• wherein the test signal generation step 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.

A signal generation method comprising:

• a test signal generation step of generating a first test signal and a second test signal;
• a correction step of correcting IQ imbalance of a generated test signal;
• and
• a calculation step of calculating, on the basis of an envelope of a modulated signal produced by modulating a corrected signal that is produced through the correction,
• wherein the test signal generation step generates a first test signal and a second test signal according to a detectable range of an envelope detector for detecting the envelope;
• and
• wherein the calculation step calculates a reference phase of the test signal on the basis of a first envelope corresponding to the first test signal, calculates a measurement phase of the test signal on the basis of a second envelope corresponding to the second test signal, and calculates correction coefficients on the basis of the measurement phase and the reference phase.