Miniaturization of the Bandpass Microwave Filter Based on Spiral Metamaterial Resonators

The purpose of this article is the miniaturization of a microwave passband filter. The miniaturized filter is a capacitive gap filter coupled in series by their ends. Our miniaturization procedure is based on the combination of the bandpass filter with periodic metamaterial resonators of spiral shape with negative permeability (μ<0). We will maintain nine (SRRs) of the same dimensions vertically to the capacitive gaps of the primary filter to control the resonance frequency of the overall structure. The dielectric substrate chosen for the etching of the capacitive resonators of the primary filter and metamaterial resonators (SRRs) is the Rogers RO 4003™ which has the dielectric constant (εr = 3.55) and the loss tangent (tanδ = 0.0027). Since there are no scientific or experimental results in the scientific literature for this type of complicated structure, we had to make simulations using the software CST Microwave Studio.