Abstract
Abstract:
Approximate equivalent circuit (EC) characterization of a novel microstrip-ring
resonator (MRR) bandpass filter (BPF) for wireless application at the ISM frequency band of
applications is presented. The proposed MRR is a combination of two bent half wavelength (λ/2)
microstrip line sections together with a pair of end-coupled microstrip feed lines (E-CMFL) of λ/8
length each. The E-CMFL forms a pestle-like shape and runs across the center of the entire
diameter. The pair is separated by a distance of 0.036λg at the center. The equivalent circuits of
the MRRs, the E-CMFL, and the effects of differing various spacing between them were investigated
using a 2D ADS circuit solver and subsequently by 3D EM commercial solvers. The findings indicate
that the proposed EC is influenced by capacitances due to a resonator gap (g), resonator-microstrip
feed line gap (d), the inter-feed line gap (i), the radius of MRRs (r), and the resonator head (m).
The EC model that was derived has been validated both by analytical
formulae and numerical simulations.