FREQUENCY MODULATION APPARATUS, POLAR MODULATION TRANSMISSION APPARATUS, RADIO TRANSMISSION DEVICE, AND RADIO COMMUNICATION DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a two-point modulation type frequency modulation apparatus capable of settling the spectrum of a transmission wave within a spectrum mask.

SOLUTION: The voltage corresponding to modulation data is supplied to a control voltage terminal of a VCO 1 via a noise shaper 101 having the characteristic that quantization noise is attenuated as a frequency increases, so that a signal level which is outputted from a PLL circuit, obtained by adding a modulation signal and quantization noise is reduced as away from a center frequency, thereby realizing the two-point modulation type frequency modulation apparatus 100 capable of settling the spectrum of an RF modulation signal within a spectrum mask.

COPYRIGHT: (C)2006,JPO&NCIPI