This paper presents the parametric studies on the effect of open circuit stub resonator (OCSR) towards the performance of Chebyshev Ultra-Wideband Stepped Impedance Low Pass Filter (SILPF). The SILPF is realized by loading OCSR to the high impedance line of the main design in order to overcome the drawback of conventional SILPF. The filter can produce sharp transition band and also wide stopband bandwidth. The design of SILPF is based on 5th order Chebyshev with 0.1 dB ripple. The filter is designed to operate at cut-off frequency 7.30 GHz. By investigating the effect of varying dimension of OSCR’s selected parameters, this paper is able to highlight the susceptibility of modifying cut-off frequency, fc and also transmission zeroes frequency, fz in order to be used for different applications. Thus, the combination of SILPF and OCSR and also rectangular patch combined feed-line structure exhibits wide rejection bandwidth better than −20 dB from 8.20 GHz up to 23.38 GHz. The filter design is simulated on Roger 4003 with relative dielectric constant, εr of 3.38 and also the substrate thickness, h of 0.508. This proposed simulated filter design has shown promising result and could be further analyzed for experimental works and fabrication. Therefore, the filter is beneficial for communication and radar systems particularly to avoid the interference and harmonic as well as the spurious response signals.
