Geração de sinais de referência para transmissores de televisão

Abstract

This work presents a theoretical and practical study of frequency synthesis techniques known as phase locked loop (PLL) and Direct Digital Synthesizer (DDS). The objective is to describe characteristic principles of two conceptions through a process of observation and comparison, identifying the better option for transmission equipment of digital signals for televisions. The chapters create divisions of the theories and practices with the aim to facilitate the development. They were established and validated with characteristic principles of a frequency synthesizer those that are directly related with the error rate of bit in a communications system and those made possible are within the established standards of government inspection agencies. The more required characteristics are the high spectral purity, the low phase noise, the high precision and exactly of synthesizer signal. Keywords: frequency synthesis, PLL, DDS, transmission equipments, digital signals for televisions.