Abstract In this research, a planar waveguide whose core is cholesteric liquid crystalline elastomer helical axis perpendicular to its boundaries, studied. The electrodynamics equations are established, together with the constitutive equations. mechanical stress tuned through elastic deformations in parallel direction along helix axis, order control propagation parameters. resulting system solv...

Oscillator and amplifier cyclotron-resonance-maser (CRM) experiments in a spiral bifilar waveguide are presented in this paper. The slow-wave CRM device employs a low-energy low-current electron beam (2-12 keV, approximately 0.5 A). The pitch angle of the helical waveguide is relatively small; hence, the phase velocity in this waveguide, V(ph) congruent with0.8c (where c is the speed of light),...

In this paper, the transfer function (TF) of a passive waveguide-based terahertz (THz) pulse shaper is calculated using time domain data provided by full-wave simulation structure. The fractional order TF determined based on response resulting from an arbitrary excitation proposed shaper. Full-wave electromagnetic numerical analyses are applied to attain time-domain output helical gold-ribbon d...

The essence of this theory is that photons are small particles of ponderable mass that travel in set helical trajectories. For any photon, the diameter of its helix may be calculated by dividing its wavelength by p (d = l/p). Further, a photon travels at a speed that is the square root of two times the speed of its helical wave, Ö2 ́ c. __________________________________________________________...

The data on which Medhurst's semi-empirical self-capacitance formula is based are re-analysed in a way that takes the permittivity of the coil-former into account. The updated formula is compared with theories attributing self-capacitance to the capacitance between adjacent turns, and also with transmission-line theories. The inter-turn capacitance approach is found to have no predictive power....

We report the experimental observation of a geometric phase for elastic waves in a waveguide with helical shape. The setup reproduces the experiment by Tomita and Chiao (Phys. Rev. Lett. 57, 1986) that showed first evidence of a Berry phase, a geometric phase for adiabatic time evolution, in optics. Experimental evidence of non-adiabatic geometric has been reported in quantum mechanics. We have...

Abstract The HE 11 hybrid mode, propagating in an overmoded corrugated circular waveguide, is widely used for low loss transmission of high-power microwaves. Due to the inherent broadband frequency behaviour, this will be also essential future radar applications, like space debris observation earth orbit (LEO). A promising amplifier concept such sensors a helical gyro-TWT. However, since mode n...