Ultra Wide Band a k a UWB Chihou

Ultra. Wide. Band a. k. a. UWB Chihou Lee : ECE 1352 : December 2003 University of Toronto - Chihou Lee

Introduction • April 2002: C U. S. Federal Communications Commission (FCC) grants new spectrum for commercial use (3. 1 GHz to 10. 6 GHz) [Aiello, 2003] University of Toronto - Chihou Lee

UWB Modulation Use IF signal to modulate RF carrier Vary delay between pulses to encode signal – PPM (pulse position modulation) University of Toronto - Chihou Lee

Transceiver Architecture [Aiello, 2003] University of Toronto - Chihou Lee

Implementation Challenges LNA & Mixer are the most challenging components to build. Designing LNA Ø narrowband LNA design no longer applies (can’t use inductive emitter degeneration) Ø Must match input/output over large frequency range Ø Very few UWB LNA implementations (1) [Sangyoub, 2002] Designing Mixer Ø Mixer uses similar matching concepts as LNA to achieve wideband matching [Sangyoub, 2002] University of Toronto - Chihou Lee

LNA Design Presenting [Sangyoub, 2003] UWB LNA design: Series-Shunt feedback Amplifier PROs: good NF, and wideband (use shunt-series to match input & output) CONs: non-optimal biasing means low gain, potential stability issues. University of Toronto - Chihou Lee

LNA Design (con’t) Three new components: L 1, L 2, Cf • L 1: Gain as freq b/c Z[L 1] = w. L 1 • L 2: Gain as freq b/c Z[L 2] = w. L 2 • Cf: decouples output from input – allows for optimal biasing. Careful consideration given to choosing component values to avoid unstable system – see [Sangyoub, 2002] University of Toronto - Chihou Lee

Summary v Ultra. Wide. Band Technology: ü Use Monopulses to carry data ü Easy circuit implementation (lower cost, power) D Can’t transmit long distance b/c low transmit power University of Toronto - Chihou Lee

References [Aiello, 2003] G. Roberto Aiello, "Challenges for Ultra-wideband (UWB) CMOS Integration". RFIC 2003. [Cravotta, 2002] Nicholas Cravotta, "Ultrawidband: the next wireless panacea? ". www. edn. com, Oct, 2002. [Sangyoub, 2002] Sangyoub Lee, "Design and Analysis of Ultra-Wide Bandwidth Impulse Radio Receiver", University of Southern California Ph. D Dissertation, 2002. [Leeper, 2003] David G. Leeper “Ultrawideband – the next step in short range wireless”, RFIC 2003 [Molisch, 2003] Andreas F. Molisch, Jinyun Zhang, “Time hopping and frequency hopping in ultrawideband systems”, IEEE 2003. [Mitchell, 2001] Terry Mitchell, “Broad is the way”, IEE Review Jan 2001. [Namgoong, 2003] Won Namgoong, “A Channelized Digital Ultrawideband Receiver”, IEEE Transactions on Wireless communications, 2003. [Siwiak, 2001] Kazimierz Siwiak, “UWB: Introducing a New Technology”, VTC 2001. [Barras] David Barras, “A Comparison between UWB and Narrowband Transceivers”. [Lerdworatawee, 2003] Jongrit Lerdworatawee, Won Namgoong, “Low Noise Amplifier Design for UWB, ” IEEE 2003. University of Toronto - Chihou Lee