Ultra-Wideband Microstrip Filter Design with Super-Shaped Defected Ground Structures

Abstract

Ultra-wideband (UWB) microstrip filter design has been proposed by applying defected ground conductor structures designed with the superformula approach. Simultaneously, the effects of the materials used in the designs on the filter properties have been examined. Once the filter characteristics have been determined, the filter design has carried out in the AWR program. The filter structure has been designed based on an 8 GHz center frequency fifth-order Chebyshev response ultra-wide bandpass filter. The filter model designed in AWR has transferred to the HFSS program, and the effect of FR4 and RO3035 materials on filter characteristics have been investigated. The various number of defects, each shaped with superformula, is opened to the base conductor, and their effects are observed. The parameters in the superformula proposed by Johan Gielis have been calculated in the MATLAB program. PCB productions of the designed filters have been made, and experimental measurements have been taken with the Anritsu spectrum analyzer. When the results obtained from electromagnetic simulation programs have compared with the experimental measurement results of the filters produced, it has been seen that the results are consistent with each other.