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An improved semi-analytical model of a lossy microstrip transmission line is proposed. The model is based on the theory of the fundamental transverse magnetic mode of a lossy parallel-plate waveguide whose dielectric medium is assigned the effective permittivity of the respective lossless microstrip line. The complex propagation constant of the fundamental mode is computed by imposing the Leontovitch boundary condition at the upper and lower plates whose impedances take into account the thickness of the conductors and the current crowding effect. The dielectric loss is computed by perturbation formulas. The proposed model features high accuracy and computational efficiency at frequencies up to 100 GHz.

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A novel analytical pseudo-nonadiabatic approach to dynamics of rotating dipolar molecules in high-gradient microwave electric fields and applications for manipulating molecules in hollow coaxial nanoreactors are considered. The translational and rotational equations of motion of a dipole in the electric and surface potentials of a nanocoax are derived using the Euler-Lagrange theorem, and their semi-analytical modifications are proposed for expediting simulations.The Maxwell distribution of initial velocities of dipoles is adopted in the simulations to take into account the effect of temperature. Using the developed approach, the translational and rotational dynamics of thermalised dipoles in the high-gradient alternating electric field of the nanocoaxial cell are studied. A relationship for the alternating field gradient force acting on the rotating dipole is derived. The regimes of attraction and repulsion of dipoles near the central nanoconductor are discovered and are shown to differently affect the translational and rotational velocities of the dipoles. The conditions for these two dynamical regimes are analytically found. The developed model and obtained results are applicable for modelling the dynamics of both 'hot' and 'cooled' dipoles in promising electrically-controlled coaxial and multiwire nanoreactors, chemical sensors, and in new molecular spectroscopes proposed in this contribution.