DISPERSION CHARACTERISTICS OF BROADSIDE COUPLED DIELECTRIC IMAGE GUIDE AT MILLIMETER-WAVE FREQUENCIES

similar to Dispersion characteristics and wave impedance for the even and odd modes of the broad side coupled dielectric image guides are co mputed by using mode matching techniques. Dispersion curves for broads ide image guide are plotted for various dielectric materials and dimen sional parameters as a function of frequency, Normalized electric fiel d for dominant electric field component E of TM even and odd modes for various half spacings between two dielectric slabs of broadside coupl ed image guide have been plotted. Polysterene (is an element of r = 2. 56) and Stycast (is an element of r = 3,4) have been used as dielectri c materials in fabricating broadside coupled image guide. This broadsi de coupled dielectric guide is very convenient as compared to the othe r dielectric guides. Since in case of broadside coupled image guide th e dielectric slab can be bonded to the side metallic walls using some low loss adhesive material, while in other coupled dielectric guides t he dielectric slab have to be supported by some low dielectric constan t material (Eccofoam with is an element of r = 1.02) to maintain the p roper distance of side metallic walls from the dielectric slab. Since this structure is symmetrical, this configuration can be analysed in t erms of even and odd mode phase velocities. The difference in these ev en and off mode phase velocities can be used to determine the coupling between coupled dielectric slab. Various couplers in this configurati on can be realised.