Theoretical investigations on the propagation characteristics of transmission lines on substrates with very high dielectric constant

The propagation characteristics of enclosed microstrip‐slot and coplanar waveguide‐slot lines printed on substrates with a very high dielectric constant (εr=40, εr=80, and εr=100, respectively) are investigated for a wide range of geometric parameters. The analysis of the lines was performed using the finite‐element method. The numerical results show the dependence of the transmission‐line parameters with transversal dimensions and frequency. Also, it was verified that the substrate thickness and enclosure width are the relevant parameters which limit single‐mode operation. © 2002 John Wiley & Sons, Inc. Microwave Opt Technol Lett 32: 275–278, 2002.