Design and analysis of slotted ring wideband bandpass filter for microwave sensor

Aiming to operate in wideband frequency range as a microwave sensor to measure the rice quality, two new design of slotted ring wideband bandpass filter design are presented in this paper. Broadside-coupled microstrip-slot technique has been implied into both designs to produce tight coupling filter with a wideband frequency range performance. Rogers RO4003C substrate with a thickness of 0.508 mm is used for the designs to maintain the low manufacturing cost. Both designs have different slotted ring widths. Therefore, investigations on the effect of difference slotted ring's widths towards the scattering parameter performance will also be presented in this paper. The simulation results show that the slotted ring wideband bandpass filter with thicker width shows better results compare to the one with thinner width. The overall results show that the designed wideband BPF possess good performance and suitable to be used as a microwave sensor to measure the rice quality