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.
