Design of x-bandpass waveguide chebyshev filter based on csrr metamaterial for telecommunication systems

A fifth-order waveguide bandpass filter is designed by two different methods, the first method used the conventional technology which rectangular waveguide cavities and direct H-plane junction. The other method used metamaterial (MM) complementary split-ring resonators (CSRR) technology, both methods are implemented with Chebyshev response. The waveguide bandpass filter is designed at X-band with 10 GHz center frequency and operates at [9.15 GHz – 10.44 GHz] bandwidth. By using the CSRR upper and lower sections that are placed on the same transverse plane and are not on the same parallel line, CSRR sections are shifted from each other. A simple model of lumped elements RLC is introduced and calculated as well for both technologies. Hereafter, by selecting proper physical parameters and optimizing the overall CSRR geometrical dimensions by taking into consideration the coupling effect between resonators; a shortened length of the overall filter and a wider bandwidth over the conventional one are obtained. As a result, the MM bandpass waveguide filter is compared with the conventional bandpass waveguide filter, in addition to other studies that have used the metamaterial technique. The MM bandpass filter reduces the overall physical length by 31% and enhances the bandwidth of up to 37.5%. An Electromagnetic (EM) simulator CST is utilized to design the filter by employing both parameters sweep and optimization techniques to achieve the required filter response. The simulation results show that the response of MM filter meets the requirements in terms of return loss, compactness and bandwidth.