AN N-TH POWER OF 2 SUB-HARMONIC FREQUENCY MODULATOR HAVING A HIGH CARRIER SUPPRESSION RATIO AND A DIRECT-CONVERSION TRANSMITTER USING THEREOF

摘要

The present invention for converting the baseband signal to a digital modulating section for outputting a digital modulation to the I component and Q component signals, the digitally modulated portion output signal of the I component and Q component signals to analog data of the I component and the Q component signal D / a conversion unit, and the analog data of the I component and Q by aligning the DC interface of the component signal passed through this low DC compensation to generate the I and Q components of the baseband signal and the low pass filter, the frequency F and a local oscillator for generating a sine wave signal _TX / 2 ^N (N is a natural number more than 1), and the multi-phase signal generator for generating a multi-phase signal having a 2 ^{N + 1} of the phase receiving the sine wave signal, the baseband 2 ^N tea low to by the I and Q components of the signal respectively, mixed with the 2 ^{N + 1} two-phase multi-phase signal having a generation of the output signal frequency F _TX waves (sub-harmonic) I / Q frequency modulator and , and a direct conversion transmitter including a power amplifier for amplifying the difference subharmonic 2 ^N I / Q frequency modulating an output signal of the output signal of the desired size, the antenna for radiating the power amplified output signal portion. ; According to the present invention, by using a signal having a frequency of 1/2 ^N of the output frequency generated by the local oscillator can improve carrier suppression ratio characteristic may be a low power consumption and miniaturization and low cost can be manufactured. ; Direct conversion, the incoming pooled, subharmonic frequency modulation, multi-phase, the ring oscillator