Electromagnetic design of high‐temperature superconducting microwave filters

Abstract

We present novel approaches to electromagnetic design of high-temperature superconducting (HTS) quarter-wave parallel coupled-line microstrip filters. The desired narrow bandwidths (less than 2%) coupled with the large dielectric constant of substrate materials used in the HTS technology (E, = 24) make the design problems difficult to treat accurately for many traditional microwave circuit design software packages with analytical/empirical models. We have successfully performed an HTS filter design with accurate electromagnetic field simulations. We discuss problems related to electromagnetic design of such filters. We describe a look-up table method and a powerful space mapping optimization technique, which dramatically reduce the CPU time needed in the design process. Finally, we address the issue of improved modeling of the HTS filter using analytical/empirical models.

An Implicit Space Mapping Technique for Component Modeling

“…2. The HTS filter (a) the physical structure [12], (b) the coarse model [5] as implemented in Agilent ADS.…”

Expanded space-mapping EM-based design framework exploiting preassigned parameters

“…4) The design variables of the high-temperature superconducting (HTS) bandpass filter (Fig. 4(a)) [14] are the lengths of the coupled lines and the separation between them Fig. 6, where we notice severe misalignment.…”

Topology bandpass filters in coplanar strip lines

“…The most widely used transmission line is microstrip line. Microstrip line bandpass filters use quarter-wavelength parallel coupled-lines and lumped elements to obtain the filter response [1][2][3].…”