ITRS: RF and Analog/Mixed-Signal Technologies for Wireless Communications

1. ITRS: RF and Analog/Mixed-Signal Technologies for Wireless Communications Nick Krajewski CMPE 640 11/16/2005

2. Introduction • 4 Working Groups within Wireless • Analog and Mixed Signal (0.8 – 10 GHz) (Covered today) • RF Transceivers (0.8 – 10 GHz) (Covered today) • Power Amplifiers and Power Management (0.8 – 10GHz) • Millimeter Wave (10-100GHz) • PA’s and Power Management and Millimeter Wave to be covered by Chandra on 11/30.

3. Analog and Mixed Signal: Scope • 1) Analog speed devices (although the speed is mainly driven by RF there are certain analog-specific needs for both high speed bipolar and CMOS) • 2) Analog precision MOS device scaling but with relatively high voltages to achieve high signal to noise ratios and low signal distortion • 3) Capacitors, and resistors; all devices are optimized for precision, matching performance, 1/f noise, low non-linearity, and low temperature gradients.

4. Analog and Mixed Signal: Difficult Challenges • Signal isolation between digital and analog regions of the chip. • Integrating analog and high-performance digital functions on a chip (scaling). Difficult to maintain analog performance parameters (mismatch and 1/fnoise together with new high-κ gate dielectrics). Transition to analog supply voltage of less than 1.8V. • Integration of analog functions in digital CMOS (depending on new materials or device structures added to digital CMOS process). Problems include SOI, double-gate devices and changes in material choices for passive devices. Transition to analog supply voltage of less than 1.0V.

5. Analog and Mixed Signal: Technology Requirements

6. Analog and Mixed Signal: Potential Solutions • SOI and SIP (combines circuits on different technologies and is optimized for desired functions) • On-chip passive components • Device matching • Integrated shielding structures

7. Analog and Mixed Signal: 2004 Updates • Technology requirements aligned for analog devices with Low Standby Power (LSTP) roadmap instead of Low Operating Power (LOP) roadmap. • Challenges for reducing 1/f noise in high-k dielectrics relaxed to color coding of yellow from red.

8. RF Transceivers: Scope • Process technologies – CMOS and Si or SiGe BiCMOS. • Applications – low noise amplifiers (LNAs), frequency synthesis and logic, voltage controlled oscillators, driver amplifiers, and filters. • Devices include NPN bipolar transistors, RF-MOS (NMOS) field effect transistors, inductors, varactors, RF capacitors, and resistors.

9. RF Transceivers: Scope cont’d • Primary metrics for performance are max frequency at unity current gain (max Ft), max frequency at unity power gain (Fmax), noise figure, and trade-offs among power, noise, and linearity. • Assumes frequency is 800 MHz to 10 GHz range. Covers GSM, CDMA, Wideband CDMA, 802.11 protocol for local area networks, and ultra wideband (UWB).

10. RF Transceivers: Scope cont’d • “RF transceiver” refers to the semiconductor content starting from the low noise amplifier (LNA) or power amplifier (PA) at the antenna end (including the LNA but not including the PA that is covered by the PA section) to the digital-to-analog converter/analog-to-digital converter (DAC/ADC) at the baseband end (not including the DAC or ADC that are covered by the mixed-signal section).

11. RF Transceivers: Difficult Challenges • Aggressive scaling of passive elements (capacitors and inductors) • Reducing cost of BiCMOS technology while improving power and performance, and improving performance of RF-CMOS devices • Signal isolation • Improving the performance (Ft and Fmax) of active devices (long term)

12. RF Transceivers: Technology Requirements

13. RF Transceivers: Potential Solutions • Improve Ft up to 300 GHz – vertical and lateral scaling • Improve Ft above 300 GHz – atomic layer epitaxy • Laterally diffused channels to improve performance of high voltage devices • Metal gates • For MIM capacitors – high-k dielectrics • For inductors – thicker layers of Cu and thicker top dielectrics

14. RF Transceivers: 2004 Updates • Similar to Near Term Table, lag between Radio Frequency (RF) CMOS gate length and BiCMOS gate length occurs in Long Term Table. • RFCMOS: technology requirements maintained 1 year lag from LSTP roadmap.

15. Questions?