Tunable Notch Filters for DAA Implementation and Its Influence on UWB System Performance

This paper presents two tunable notch filters (TNFs) for detect-and-avoid (DAA) implementation in an ultra-wideband (UWB) radio system. The developed filters have relatively wide- and narrow-stopband, respectively, using two different resonant structures. A system experiment has been carried out to evaluate the influence of bandwidth of notch band on the system performance when the two different filters are implemented for the DAA. The UWB system used in the evaluation is a multi-band OFDM-based system. The experimental results clearly show the different influences with different bandwidth of notch band on the system performance both from the signal spectrum and throughput of the data transmission. The narrow band tunable notch filter improves receiving sensitivity by about 3 dB compared with the wide band filter.