INTRODUCTION xxi
Figure .1: Illustration of Moore’s Law.Lasers and detectors have been the enabling elements in optical communications. Lasers have
also enabled entertainment devices such as the DVD.
The continuous expansion of the material and device tool set has enabled system designers
to choose the correct technology for the application, resulting in phenomenal advances at the
system level. This is best understood by studying a commercial widespread system - the cellular
phone. Consider the Motorola V551 phone, illustrated in figure .2. The key components of the
transmit/receive chain in any radio architecture are the switch, filter, modulator/demodulator,
LNA, mixer, gain blocks, and power amplifier. Integrating the different chips into a total radio
solution places varied specifications on the different chips used to achieve the radio solution. In
turn, these specifications drive the selection of the active device and process technology that is
used to implement the functionality of the particular chip.
As an example of this technology selection process, consider the POLARIS total radio solution
from RFMD, which is a highly integrated transciever that performs all functions of the handset
radio section, operating under GSM/GPRS/EDGE standards. The POLARIS chipset consists of
the following functional blocks, shown in figure .3:
- The RF 2722 quad-band RF receiver.
- The RF 3146 POWER STAR PA module with integrated power control.
- The RF 6001 digital filter, fractional-N PLL, modulator, and power amplifier ramp control.