A compact triple-band bandstop filter

This paper presents a compact triple-band bandstop filter (TBBSF) that features three controllable stopbands at 1.8 GHz, 5.2 GHz and 8.5 GHz frequencies. A drastic reduction in size of the filter was achieved by taking advantage of a simplified architecture based on E-shaped resonator. The return losses of the simulated filter are measured to be -46.14, -38.93 and -37.82 dB while the insertion losses are -0.01, -0.2 and -0.3 dB at the respective stop bands. Due to its compact size and satisfactory stopband performance, the filter can be useful for modern communication technology.