Derek Shaeffer - Böcker
Visar alla böcker från författaren Derek Shaeffer. Handla med fri frakt och snabb leverans.
2 produkter
2 produkter
1 069 kr
Skickas inom 10-15 vardagar
The primary goal of this work is to explore techniques for implementing wireless receivers in an inexpensive complementary metal-oxide-semiconductor (CMOS) technology. Although the techniques developed apply somewhat generally across many classes of receivers, the specific focus of this work is on the Global Positioning System (GPS). Because GPS provides a convenient vehicle for examining CMOS receivers, a brief overview of the GPS system and its implications for consumer electronics is presented. The GPS system comprises 24 satellites in low earth orbit that continuously broadcast their position and local time. Through satellite range measurements, a receiver can determine its absolute position and time to within about 100m anywhere on Earth, as long as four satellites are within view. The deployment of this satellite network was completed in 1994 and, as a result, consumer markets for GPS navigation capabilities are beginning to blossom. Examples include automotive or maritime navigation, intelligent hand-off algorithms in cellular telephony, and cellular emergency services, to name a few.Of particular interest in the context of this book are embedded GPS applications where a GPS receiver is just one component of a larger system. Widespread proliferation of embedded GPS capability will require receivers that are compact, cheap and low-power.
1 069 kr
Skickas inom 10-15 vardagar
It is hardly a profound observation to note that we remain in the midst of a wireless revolution. In 1998 alone, over 150 million cell phones were sold worldwide, representing an astonishing 50% increase over the previous year. Maintaining such a remarkable growth rate requires constant innovation to decrease cost while increasing performance and functionality. Traditionally, wireless products have depended on a mixture of semicond- tor technologies, spanning GaAs, bipolar and BiCMOS, just to name a few. A question that has been hotly debated is whether CMOS could ever be suitable for RF applications. However, given the acknowledged inferiority of CMOS transistors relative to those in other candidate technologies, it has been argued by many that “CMOS RF” is an oxymoron, an endeavor best left cloistered in the ivory towers of academia. In rebuttal, there are several compelling reasons to consider CMOS for wi- less applications. Aside from the exponential device and density improvements delivered regularly by Moore’s law, only CMOS offers a technology path for integrating RF and digital elements, potentially leading to exceptionally c- pact and low-cost devices. To enable this achievement, several thorny issues need to be resolved. Among these are the problem of poor passive com- nents, broadband noise in MOSFETs, and phase noise in oscillators made with CMOS. Beyond the component level, there is also the important question of whether there are different architectural choices that one would make if CMOS were used, given the different constraints.