Broadside-coupled rectangular resonators in suspended stripline with single and double dielectrics

The rigorous spectral domain method is applied to analyse the resonant frequency characteristics of rectangular resonators in three broadside-coupled suspended stripline configurations. These are (a) broadside-coupled suspended stripline with a single dielectric (b) broadside-coupled suspended stripline with double dielectrics and (c) broadside-coupled suspended stripline with double inverted dielectrics. Computed dominant even- and odd-mode resonant frequencies of rectangular resonators in the above broadside-coupled configurations are presented as a function of various structural parameters. These characteristics are distinct from those obtained for conventional edge-coupled microstrip resonators. The computed resonant frequencies using simple basis functions are compared with the experimental values in the frequency range 5-13 GHz. The results presented in this paper should find application in the design of microwave and millimeter wave integrated circuit components.