Patent attributes
A transmission circuit includes: a modulated signal generator; a modulated signal line where an OFDM modulated wave flows; a detector; a phase component line for transmitting a phase component; an amplitude component line for transmitting an amplitude component; a level judging circuit for judging the level of the amplitude component; a constant-voltage supply line; first and second selectors; a quadrature converter; and an RF power amplifier. An EER or pseudo-EER technique is performed in a region where the RF input-output characteristic of the RF power amplifier with an EER technique exhibits a linear response, whereas usual modulation is performed in a region where a nonlinear response is exhibited. The modulation method is switched using the level judging circuit and the selectors with reference to a threshold value which is the boundary between the region where the linear response is exhibited and the region where the nonlinear response is exhibited.
