Microwave losses in electrodes of distributed and lumped ferroelectric-based elements

The microwave losses in electrodes of a ferroelectric-based transmission line and a lumped ferro-electric-based element have been theoretically analyzed. The results of calculations of the effective loss tangent for the transmission line are confirmed by a two-dimensional electrodynamic model analysis and by experiments with a coplanar phase shifter. It is established that the use of microwave devices based on ferroelectric lumped elements is expedient in the 1-50 GHz frequency range (that is, in most microwave applications). The microwave losses in electrodes are significantly lower for lumped elements than for a long transmission line. These losses are determined by the ratio of the depth of electromagnetic field penetration into a conductor (superconductor) to the interelectrode gap width and are independent of the dielectric permittivity.