Second harmonic suppression in helix traveling-wave tubes
A filter structure to suppress the second harmonic component in the RF signal of a traveling-wave tube (TWT) was developed and integrated into a helical delay line. Its effect is shown in simulation and measurement.
Simulation of multi-reflections in a helix-type TWT
A model of the reflections occurring at discontinuities in the delay-line of a helix-type traveling-wave tube (TWT) is being integrated into the interaction simulation code MVTRAD. First results are presented.
Explicit solutions for N-dimensional Schrödinger equations with position-dependent mass
With the consideration of spherical symmetry for the potential and mass function, one-dimensional solutions of nonrelativistic Schrodinger equations with spatially varying effective mass are successfully extended to arbitrary dimensions within the frame of recently developed elegant nonperturbative technique, where the BenDaniel-Duke effective Hamiltonian in one dimension is assumed like the unperturbed piece, leading to well-known solutions, whereas the modification term due to possible use of other effective Hamiltonians in one dimension and, together with the corrections coming from the treatments in higher dimensions, are considered as an additional term like the perturbation. Application of the model and its generalization for the completeness are discussed.