@INPROCEEDINGS {1230,
author={M. G. Silveirinha and C. A. Fernandes},
doi={10.1109/APS.2003.1220411 },
booktitle={IEEE AP-S/URSI International Symp.},
title={Design of Waveguide Filters Using a PBG Disk-Type Material},
year={2003},
month={June},
volume={4},
pages={875-878} 
}