Papers covered: recent developments in rubidium, cesium, and hydrogen-based frequency standards, and in cryogenic and trapped-ion technology; international and transnational applications of PTTI technology with emphasis on satellite laser tracking networks, GLONASS timing, intercomparison of national time scales, and international telecommunications; applications of PTTI technology to the telecommunications, power distribution, and platform positioning, and geophysical survey industries; applications of PTTI technology to evolving military communications and navigation systems; and dissemination of precise time and frequency by means of GPS, GLONASS, MILSTAR, Loran, and synchronous communications satellites.

With the advent of integrated circuits (IC), digital systems havebecome widely used in modern electronic devices, includingcommunications and measurement equipment. Direct Digital FrequencySynthesizers (DDS) are used in communications as transmitterexciters and local oscillators in receivers. The advantages aresuperior frequency stability, the same as that of the driving clockoscillator, and short switching times. The difficulties are loweroutput frequencies and rather large spurious signals. Compiled for practicing engineers who do not have theprerequisite of a specialist's knowledge in Direct DigitalFrequency Synthesizers (DDS), this collection of 40 importantreprinted papers and 9 never-before published contributionspresents a comprehensive introduction to DDS properties and a clearunderstanding of actual devices. The information in this volume canlead to easier computer simulations and improved designs. Featured topics include: * Discussion of principles and state of the art of wide-rangeDDS * Investigation of spurious signals in DDS * Combination of DDS with Phase Lock Loops (PLL) * Examination of phase and background 'noise' in DDS * Introduction to Digital to Analog Conversion (DAC) * Analysis of mathematics of quasiperiodic omission ofpulses DDFS can also serve as a textbook for students seeking essentialbackground theory.