Strontium titanate thin films for tunable YBa/sub 2/Cu/sub 3/O/sub 7/ microwave filters

Analysis and Simulation of distributed nonlinearities in ferroelectrics and superconductors for microwave applications

“…These parameters can be related to HTS intrinsic nonlinearities as follows: the nonlinear resistance is due to nonlinearities in quasi-particle conductivity and the nonlinear inductance is due to nonlinearities in penetration depth. At sufficiently small currents, we should expect a quadratic dependence of the overall inductance and resistance per unit length on the total current through the cross section of the TL with (1) with (2) where and are positive to be consistent with the model of intrinsic nonlinearities in HTS TLs [11], [19]. These nonlinear terms just add to the linear , , , and distributed elements of the model of a TL (Fig.…”

“…The combination of high-temperature superconductors (HTSs) and oxide ferroelectrics is also being considered to produce selective tunable filters with low loss [2], [3]. However, these expectations are somewhat limited by nonlinearities arising from the use of these materials, either when used alone (such as in an HTS filter) [4], [5] or in combination (such as in an HTS tunable filter using oxide ferroelectrics).…”

Growth of high-quality large-area MgB2thin films by reactive evaporation

“…The technique utilizes a rotating pocket heater of a type similar to that developed f or deposition of large-area HTS [13,14] and other oxide [15,16] thin films. Such a heater is routinely employed for high-throughput production of (RE)BCO films.…”

Measurements and Analysis of Microwave Nonlinearities in Ferroelectric Thin Film Transmission Lines

“…Note that AC(Vdc) is analogous to A6-'r(E) defined in (1), the quadratic coefficient of which (A,-'rq(E)) is also reported in Table I. To compare (2) and (3) we also use a square law dependence to fit the measurements of C(Vdc). That is AC(Vdc)= AC2 dc V2dc [8].…”

“…The combination of these materials with high temperature superconductors (HTS) is being considered to achieve lowloss filters with electronic frequency tuning/trimming features [2], or to reduce the nonlinear effects inherent to HTS components [3].…”