Three Pole Wideband Waveguide Bandpass Filter using Split Ring Resonator Integrated Circular Fractal Shape

Abstract

AbstractThis paper presents an alternative concept of metal insert to design compact, wideband, waveguide bandpass filter. Three planar circular fractals, integrated with Split Ring Resonators, have been placed on the transverse plane of a standard WR–90 waveguide at quarter wavelength distance to form the wideband, tri-pole bandpass filter. The proposed filter has been simulated using Ansoft HFSS (version 14) and using equiripple Chebyshev approximation its lumped element equivalent circuit has been obtained. The filter was also fabricated and its frequency response has been measured. The measured result shows a 3-dB fractional bandwidth of 14.08 % at resonant frequency 10.15 GHz. The total length of the filter is 20.33 mm. Detailed design procedure has been presented along with necessary diagram. A table has been provided to compare the performance of the proposed filter with those already available in literatures. The table shows that the proposed filter is compact, has higher bandwidth and better frequency response compared to the rests.