SHIFTING THE OPERATING FREQUENCY BAND OF THE WAVEGUIDE FILTER BY CHANGING CSRR TYPE META RESONATORS IN THE SINGLE WAVEGUIDE

Abstract

In this study, bandpass waveguide filters with resonant frequencies of 5.5 GHz, 6 GHz, and 6.5 GHz are simulated and fabricated by Computer Numerical Control (CNC) milling method. Then, the simulated and measured performance parameters are obtained and compared from 1st order to 7th filter order. By using the same WR-159 waveguide structure, the operating frequency band can be easily shifted by changing only Complementary Split Ring Resonator (CSRR)-type meta-resonators placed in the waveguide, so that the same waveguide structure can be used as a filter in different frequency band regions. The measured insertion loss (IL) values are found to be within the intervals of 0.3-1.88 dB, 0.06-0.49 dB, and 0.43-2.24 dB for the waveguide filters (WGF) at resonance frequencies of 5.5 GHz, 6 GHz, and 6.5 GHz, respectively. Simulated and measured resonance frequencies have good agreement with each other for all filter orders and these values are sufficient to use the filters proposed in this study in many applications.