Patent ID: 9584349
Date: 2017-02-28
CPC Classifications: H03F,H04L

Claim:
1. A transmission circuit comprising: a delta-sigma modulator that performs delta-sigma modulation on an amplitude component signal of a baseband signal to output an amplitude pulse-modulated signal, an orthogonal modulator that performs orthogonal modulation on an angular component signal of the baseband signal with a carrier wave to output a phase-modulated signal, and a first multiplier that multiplies the amplitude pulse-modulated signal and the phase-modulated signal to output the result of the multiplication to a power amplifier, the transmission circuit further comprising: a comparator that converts the phase-modulated signal into a pulse signal; and an asynchronous clock transfer device and an interpolating circuit, disposed between a baseband clock circuit, based on a baseband clock, and the delta-sigma modulator, wherein the delta-sigma modulator uses the pulse signal as a sampling clock, the asynchronous clock transfer device converts the amplitude component signal synchronized with the baseband clock into an amplitude component signal synchronized with an N-frequency divided clock by dividing the frequency of the sampling clock by N, wherein N is a natural number equal to or greater than 2, and outputs the converted amplitude component signal to the interpolating circuit, and the interpolating circuit interpolates the output signal from the asynchronous clock transfer device, so that the amount of change of one sample in the N-frequency divided clock becomes equal to the amount of change of one sample in the sampling clock, and outputs the interpolated signal to the delta-sigma modulator.