To address the demanding requirements of the emerging wireless, mobile and wire-line applications, semiconductor suppliers continue to refine older technologies while developing new technologies. As a result, new trends will emerge in both discrete device and IC technologies. Improved RF power transistors promise to give wireless infrastructure power amplifiers new levels of performance with better reliability and ruggedness, while RFICs hope to extend the role of CMOS to enable emerging mobile handsets to deliver multimedia functions from a compact package at lower cost. And, incumbents like gallium arsenide (GaAs), have moved to higher voltages to keep the pace going.

As discussed in this issue's cover report, the ongoing improvements in process, qualification and production has propelled gallium nitride (GaN) RF power transistors to the production phase. Thus, ready to make a dent in the infrastructure space, as well as capturing sockets in military and microwave communications. Both GaN-on-silicon as well as GaN-on-SiC-based RF power transistors will be offered. As GaN devices gain momentum, the dominant LDMOS will continue to strengthen its position as it also looks for greener pastures. Like others, LDMOS suppliers are pushing the frequency capability beyond 2 GHz to enter the emerging WiMAX domain. Analysts predict that despite encroachment from CMOS and BiCMOS, GaAs HBT and pHEMT processes will see increased capacity with a new expansion plan this year.

Improvements in integration envelope for GaAs ICs and the ability to operate at higher voltages will give this technology a new lease on life. The rapid trend toward complex multiband, multimode cellular and mobile handset designs with integrated front-end modules will continue to drive the consumption of compound semiconductor HBTs and pHEMTs in emerging handsets, while the ability to deliver linear, rugged high-power Pas at 24 V to 28 V will open the infrastructure door for GaAs HBTs.

As memory makers pace to sample 16 Gbit flash memories to key customers using 50 nanometer CMOS process, developers of RF CMOS SoCs will quickly migrate to 65 nm node to narrow the technology gap. Motivated to pack RF transceivers and baseband processing on a single die, single-chip phone developers are moving from 0.18 µm and 0.13 µm CMOS to 90 nm node and below. In fact, one key single-chip cell phone supplier is in the process of redesigning an older version in 65 nm CMOS node. And, there will be more such deep nm CMOS demonstrations this year. Speaking of innovations in nm CMOS, this year's IEEE International Solid-State Circuits Conference (ISSCC) in San Francisco, Calif. will give us a peek into emerging advances in CMOS RFICs as the technology makes strong inroads into microwave and milli-meter-wave territory. For instance, papers here on ultrawideband (UWB) transceivers represent significant strides in nm RF CMOS realization. And advances in single-chip 60 GHz band transceivers for emerging automotive radar, medical imaging and security applications, break new grounds for millimeter-wave CMOS. What was considered unthinkable a decade or so ago, is now a reality.

Meanwhile, for high-power applications like switching as well as amplification, CMOS will continue to tap other resources such as SiGe bipolar and SOI technologies. Also, this year MEMS will see more integration with CMOS. Papers to be reported at ISSCC 2007 indicate that advanced micromachined devices are being integrated with CMOS signal processing and conditioning circuits for high-volume markets such as mobile phones and portable electronics. According to a new study from market research firm ABI Research, 2008 will be the take-off year for MEMS in the mobile phone as the technology's small size, flexibility and performance advantages become big draw cards, critical to enabling the adaptive, multifunction handsets of the future.

In reality, both old and new RF semicon-ductor technologies will go forward side by side. Learning from each other and remedying their drawbacks to gain more market share.