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Open Access

Principles and Limitations of Ultra-Wideband FM Communications Systems

  • John F.M. Gerrits1Email author,
  • Michiel H.L. Kouwenhoven2,
  • Paul R. van der Meer3,
  • John R. Farserotu1 and
  • John R. Long3
EURASIP Journal on Advances in Signal Processing20052005:189150

Received: 10 October 2003

Published: 17 March 2005


This paper presents a novel UWB communications system using double FM: a low-modulation index digital FSK followed by a high-modulation index analog FM to create a constant-envelope UWB signal. FDMA techniques at the subcarrier level are exploited to accommodate multiple users. The system is intended for low (1–10 kbps) and medium (100–1000 kbps) bit rate, and short-range WPAN systems. A wideband delay-line FM demodulator that is not preceded by any limiting amplifier constitutes the key component of the UWBFM receiver. This unusual approach permits multiple users to share the same RF bandwidth. Multipath, however, may limit the useful subcarrier bandwidth to one octave. This paper addresses the performance with AWGN and multipath, the resistance to narrowband interference, as well as the simultaneous detection of multiple FM signals at the same carrier frequency. SPICE and Matlab simulation results illustrate the principles and limitations of this new technology. A hardware demonstrator has been realized and has allowed the confirmation of theory with practical results.

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Authors’ Affiliations

Centre Suisse d'Electronique et de Microtechnique SA, Neuchâtel, Switzerland
National Semiconductor BV, Amplifier Design Europe, Delft, The Netherlands
Electronics Research Laboratory/DIMES, Faculty of Electrical Engineering, Mathematics and Computer Science (EEMCS), Delft University of Technology, Delft, The Netherlands


© Gerrits et al. 2005

This article is published under license to BioMed Central Ltd. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.