A major advantage of a direct digital synthesizer (DDS) is that its output frequency, phase and amplitude can be precisely and rapidly manipulated under digital processor control. Other inherent DDS attributes include the ability to tune with extremely fine frequency and phase resolution, and to rapidly ‘hop' between frequencies. These combined characteristics have made the technology popular in military radar and communications systems. In fact, DDS technology was previously applied almost exclusively to highend and military applications: it was costly, powerhungry, difficult to implement, and required a discrete high speed D/A converter. Due to improved integrated circuit (IC) technologies, they now present a viable alternative to analogbased phaselocked loop (PLL) technology for generating agile analog output frequency in consumer synthesizer applications. It is easy to include different modulation capabilities in the DDS by using digital signal processing (DSP) methods, because the signal is in digital form. By programming the DDS, adaptive channel bandwidths, modulation formats, frequency hopping and data rates are easily achieved. The flexibility of the DDS makes it ideal for signal generator for software radio. The digital circuits used to implement signalprocessing functions do not suffer the effects of thermal drift, aging and component variations associated with their analog counterparts. The implementation of digital functional blocks makes it possible to achieve a high degree of system integration. Recent advances in IC fabrication technology, particularly CMOS, coupled with advanced DSP algorithms and architectures are providing possible singlechip DDS solutions to complex communication and signal processing subsystems as modulators, demodulators, local oscillators, programmable clock generators, and chirp generators. The DDS addresses a variety of applications, including cable modems, measurement equipments, arbitrary waveform generators, cellular base stations and wireless local loop base stations. Direct Digital Synthesizers was written to find possible applications for radio communication systems. It will have appeal for wireless and wireline communication engineers, teachers and students.
A major advantage of a direct digital synthesizer (DDS) is that its output frequency, phase and amplitude can be precisely and rapidly manipulated under digital processor control. Other inherent DDS attributes include the ability to tune with extremely fine frequency and phase resolution, and to rapidly ‘hop' between frequencies. These combined characteristics have made the technology popular in military radar and communications systems. In fact, DDS technology was previously applied almost exclusively to highend and military applications: it was costly, powerhungry, difficult to implement, and required a discrete high speed D/A converter. Due to improved integrated circuit (IC) technologies, they now present a viable alternative to analogbased phaselocked loop (PLL) technology for generating agile analog output frequency in consumer synthesizer applications. It is easy to include different modulation capabilities in the DDS by using digital signal processing (DSP) methods, because the signal is in digital form. By programming the DDS, adaptive channel bandwidths, modulation formats, frequency hopping and data rates are easily achieved. The flexibility of the DDS makes it ideal for signal generator for software radio. The digital circuits used to implement signalprocessing functions do not suffer the effects of thermal drift, aging and component variations associated with their analog counterparts. The implementation of digital functional blocks makes it possible to achieve a high degree of system integration. Recent advances in IC fabrication technology, particularly CMOS, coupled with advanced DSP algorithms and architectures are providing possible singlechip DDS solutions to complex communication and signal processing subsystems as modulators, demodulators, local oscillators, programmable clock generators, and chirp generators. The DDS addresses a variety of applications, including cable modems, measurement equipments, arbitrary waveform generators, cellular base stations and wireless local loop base stations. Direct Digital Synthesizers was written to find possible applications for radio communication systems. It will have appeal for wireless and wireline communication engineers, teachers and students.
Barnes & Noble is the world’s largest retail bookseller and a leading retailer of content, digital media and educational products. Our Nook Digital business offers a lineup of NOOK® tablets and e-Readers and an expansive collection of digital reading content through the NOOK Store®. Barnes & Noble’s mission is to operate the best omni-channel specialty retail business in America, helping both our customers and booksellers reach their aspirations, while being a credit to the communities we serve.
