CHARACTERISTICS OF DIELECTRIC-LINE-LOADED CONDUCTOR-BACKED SLOTLINE (CBS)

The mode-coupling phenomenon prevents the conventional shielded conduc tor-backed slotline (CBS) from broadband applications. This paper prop oses a modified CBS by adding a dielectric line of higher dielectric c onstant on the top of the dot region to circumvent the mode-coupling p roblem. The dispersion characteristics of the resultant dielectric lin e-loaded CBS are studied by using the full-wave space-domain Green's i mpedance. function approach. The theoretic results show that the parti cular modified CBS significantly reduces mode-coupling phenomenon and is suitable for broadband applications. Furthermore, it is possible to adjust the values of the propagation constant and the characteristic impedance by changing the thickness of the dielectric line on top of t he slot region. Finally, the design curves for the dielectric line-loa ded CBS are provided for potential applications.