An Integrated, Low Power, Ultra-wideband Transceiver Architecture for Low-rate, Indoor Wireless Systems

Ian D. O’Donnell, Mike S. W. Chen, Stanley B. T. Wang, Robert W. Brodersen
 IEEE CAS Workshop on Wireless Communications and Networking, Sept. 5-6, 2002

This paper describes the system architecture and circuit design constraints for a proposed Ultra-Wideband radio transceiver. Targeting a sensor network application, the radio supports peer-to-peer communication at greater than 100kbps over 5 meters with a 1mW total (TX+RX) power budget. A narrow pulse (approximately 1ns wide) is transmitted using simple digital switches; spreading the energy over a Gigahertz of bandwidth. Reception, after gain and filtering, occurs in a bank of A/D converters which capture the received pulse in an adjustable window of 16 to 64ns. This window is composed of 32 to 128 data samples at a 2GHz rate and is repeated at the pulse broadcast frequency which may range from 62.5MHz to 1MHz. The implementation issues of this system, including clock generation, conversion bit-widths, gain, and the choice of pulse rate versus pulse amplitude will be discussed along with the subject of interference and the idea of "imperceptible" operation.