Narrowband interferer analysis and attenuation

Description of research

Wideband analog to digital converters have a limited dynamic range. This limitation arises out of analog design issues; increasing the dynamic range of an A/D converter by 1 bit roughly doubles the amount of dissipated power. This constraint forms a problem when designing wideband digital receiver circuits.

Small bandwidth digital receivers employ analog mixing stages and filters; these receiver circuits provide a baseband signal at the A/D converter input. This signal is suitable for analog to digital conversion; closely situated interferers and adjacent noise can be filtered out. A wideband receiver can be implemented by omitting the mixer and filter stages, directly offering a received wideband signal to the A/D. This topology works when the antenna e.g. captures a UWB signal having a very constant spectral density across its bandwidth. However if this flat spectrum is contaminated by high power narrow-band interfering signals, the total dynamic range of the received signal increases. This dynamic range cannot be captured by a wideband A/D converter.

The aim of this project is to figure out which possibilities exist that facilitate the capture of the abovementioned contaminated wideband signal, without the need of a hypothetical high-bandwidth high-resolution A/D converter. Properties of narrow-band signals are investigated in order to obtain the most efficient way of attenuating small band interferers. Qualitatively, the goal is to increase the effective resolution of the total A/D converter system by using an attenuation technique. Increasing the A/D converter resolution this way would not lead to excessive power dissipation.

Advisor(s)

Prof. ir. A.J.M. van Tuyl

Prof.dr.ir. Bram Nauta

Duration

July 2006 – July 2010

Project

Wideband A/D interferer analysis and attenuation

Funding institution

NXP Semiconductors

Strategic Research Orientation

Wise-Wireless and Sensor Systems

Links to relevant web pages:

N/A

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