Fundamental limits of the linear microwave power response of epitaxial Y-Ba-Cu-O films

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

“…While this intrinsic contribution sets the minimum level of nonlinearities [13], other extrinsic nonlinearities due to material defects may further enhance nonlinear distortions [14]- [16].…”

Microstructure and microwave surface resistance of typical YBaCuO thin films on sapphire and LaAlO3

“…Less is known so far about the relation between microstructure and the nonlinear increase of R s with the amplitude B s of the microwave field [11]. From a general point of view, nonlinear microwave response can be attributed to magnetic effects (basically penetration of Abrikosov and/or Josephson vortices) and microwave heating [12,13]. Both sources can occur locally at certain defects, or globally across the film area.…”

Numerical computation of the interaction between electromagnetic waves and nonlinear superconducting materials

“…In this case, the above formulation for the nonlinear scattering problem can be reduced to a scalar one and, by analogy to [35], (19) can be rewritten as (22) where is the cross section of the scatterer, , is the Hankel function of the second kind and the zeroth order, and is the scalar analogous to in relation (18).…”

“…The generation of higher order harmonics and their effects on the field at the fundamental frequency is taken into account via the coupling term . After discretization of the continuous model represented by the integral (22), for , the problem solution is reduced to the solution of an algebraic system of nonlinear equations [29]. In particular, if we consider a fixed number of harmonic components (a series truncation is performed) and after expanding and into the sum of basis functions with the coefficients and ( ), the resulting system can be expressed as (23) where the coefficients and are obtained as in [35] by applying the Richmond formulation [38], which has been proven to be accurate for the forward scattering by a dielectric cylinder if a TM illumination is used [39].…”