Ultra Wideband Digital Wireless Link By Matthew Carrier, Nicholas Merrill, Brandon Mui, Justin Burkhart Advisor: Professor R.W. Jackson

What is Ultra Wide Band?  Ultra Wide Band (UWB) uses very low-powered, short pulsed radio signals to transfer data over a wide range of frequencies  FCC Definition:  Signals must occupy bandwidth >500MHz  Or, signal bandwidth is 20% of the carrier frequency

Why do we need Ultra Wide Band?  High-tech designs require portability, speed, & performance  Portability:  UWB use multiple low-powered pulses → low power consumption  UWB data rate is inversely proportional to distance (thus short range)  Speed:  Proposed to be between Mb/s, and eventually up to Gb/s  Performance:  Volume of information proportional to the frequency band  More information → better graphics, better resolution for RADAR, etc.

 Standard TR-UWB systems are “dogged” by implementation issues  The receiver requires an extremely wideband delay element  As a solution, Professor Goeckel has developed theory for Slightly Frequency Shifted Reference UWB Transmitted Reference UWB Systems t data Reference (Transmitted Reference UWB)

Slightly Frequency Shifted UWB  Rather then separating the data from the reference in time, this systems separates them in frequency  Data and Reference pulse must be orthogonal in frequency  This avoids using the extremely wideband delay element in the receiver  Our project is to take Prof. Goeckel’s theory and prove the concept through building a scaled prototype

Deliverables Deliverables  Transmitter/Receiver Electronics Prototype  Transmitter/Receiver Antenna Prototype  Packaging design is not part of project

 Omni antenna  Pulse Generator has pulses with picosecond rise times  Oscillator used for frequency shifting of the pulses  PLD is used for buffering of data Transmitter PLD Input Pulser Oscillator X X Σ

Receiver  Omni antenna  Oscillator at same frequency and phase as transmitter (sync not yet designed)  PLD is for out-buffering of received data X X Oscillator PLD Integrator

What is Missing?  Need to design circuitry to synchronize the frequency shift oscillators  Need to develop/buy integrator circuitry that can be triggered  Integrator and PLD sampling also have sync issues that need to be worked out  Antenna design has yet to be implemented  An antenna in our channel has already been designed by grad students here at UMASS

Pulse Generation: Closer Look  Create very fast pulses using Step Recover Diodes (SRD)

MDR Specification  Transmitter & Receiver prototype built  Built using modular components connected with coaxial cable  No synchronization circuitry implemented  No antenna implemented  Antenna design & prototype built  Tested for gain, return loss, & radiation patterns  Synchronization Circuitry  Will be designed independently from the prototype

Questions/Suggestions? ?