Conductor Gap Research Articles

Hybrid plasmonic modes in a quantum cylindrical system in the presence of a nanoscale gap region

Theoretical analysis of hybrid plasmon polariton (HPP) wave in a cylindrical conductor–gap–dielectric structure is presented using the quantum hydrodynamic model. Numerical results show the quantum effects, including the Fermi pressure and the Bohm potential have little effect on the dispersion relations of the HPP wave in the cylindrical plasmonic system. We find that the propagation of the HPP wave in the cylindrical CGD structure is very sensitive to the radius of the metal cylinder, the thickness of the gap layer, and the permittivity of the dielectric mediums. These results will be useful for understanding the properties of the hybrid surface waves in cylindrical nanostructures.

Characteristics of Quantum Plasmonic Waves Guided by a Symmetric Metal–Gap–Dielectric Nano-system

The guiding properties of a symmetric conductor–gap–dielectric system consists of a metal film symmetrically surrounded by media of two dielectrics, and is theoretically analyzed by using the quantum hydrodynamic model and Maxwell’s equations. We found that the quantum effects, including the Fermi pressure and the Bohm potential, facilitate the propagation of the hybrid surface waves at higher values of the wavenumber. The results show that the permittivity of the surrounding dielectric mediums and the geometric effects (namely, the thickness of the metal film and gap layers) significantly modify the basic behaviors of the hybrid surface waves. Our results provide a good understanding of the basic features of the wave propagation phenomenon in hybrid waveguide systems.

Theoretical study of surface waves in a magnetized conductor-gap-dielectric nano-structure

External magnetic field effects on the dispersion properties of hybrid plasmon polariton (HPP) modes are theoretically investigated in a collisional warm magnetized planar conductor–gap–dielectric (CGD) system. This structure consists of a high index dielectric, separated from a warm metallic plasma with a low index nano-sized dielectric layer. The Magnetohydrodynamics model (MHD) coupled to Maxwell’s equations is used to derive the new dispersion relation of HPP waves in the CGD system. Numerical results reveal that the weakly external magnetic field which is parallel to the propagation wave has a significant effect on the dispersion properties of the guide modes and leads to an increase in the surface wave’s confinement and the propagation length of the HPP mode. Also, it is found that the critical gap thickness in the magnetized CGD system is bigger than the critical thickness in the unmagnetized CGD system.

First-Order Modeling of Errors Due to Coaxial Connector Interface

We present an approach for first-order modeling of errors in vector-network-analyzer (VNA) measurements caused by the coaxial-connector interface. These errors result primarily from the presence of a gap in the inner conductor. Our approach relies on an approximate model of the connector interface that comprises an analytical equivalent-circuit for the inner conductor gap section and a behavioral scattering-parameter model for the socket-contact section. We verify this model using full-wave electromagnetic simulations for the 1.85, 2.4, 3.5 mm, and Type-N coaxial-connector interface for different inner conductor-gap widths. We further apply this model to asses first-order errors in VNA calibration introduced by the tolerance on the inner conductor-gap width. We show that the inner conductor-gap effect can be accounted for with a series inductance inserted at the inner conductor mating-plane while the effect of the socket contact can be lumped into the VNA calibration coefficients. We verify this error model experimentally by measuring a Type-N offset load with an adjustable inner conductor gap. We also demonstrate that including our error model in coaxial offset-short definitions leads to improved consistency of a one-port VNA calibration with 3.5-mm coaxial offset-short standards. Our results can be used in the uncertainty analysis and accuracy enhancement of VNA scattering-parameter measurements.

Propagational characteristics in a warm hybrid plasmonic waveguide

We theoretically analyze the properties of guided modes in a warm planar conductor–gap–dielectric (CGD) system. The latter consists of a high index dielectric, separated from a warm metallic plasma with a low index nano-sized dielectric layer (gap) by using the hydrodynamic model coupled to Maxwell's equations. The effects of thermal pressure on the confinement and the propagation losses of Hybrid Plasmon Polariton (HPP) modes are studied. We found that the thermal effect leads to a reduction in the effective refractive index as well as in the propagation losses of the HPP mode. Furthermore, the cutoff thickness in the warm CGD waveguide is found to be smaller than that in a cold CGD waveguide. The results may be useful in understanding the essential physics of active/passive Plasmonic devices and chip-scale systems.

Low power hybrid plasmonic microring-on-disks electro-optical modulators

Different electro-optical modulator designs based on electromagnetically induced transparency are proposed. A conductor–gap–silicon input waveguide is coupled to microrings-on-disks on each side. A low voltage modulating signal is applied to the modulator in a push-pull configuration, which changes the refractive index of the embedded layer of the electro-optical polymer. The proposed microrings-on-disks and cascaded microring modulators with submicron radii can efficiently modulate the light wave with moderate propagation losses. The microring-on-disk modulator achieved ultrasmall capacitance, 1.06 fF, and low power consumption, 2.12 fJ/bit. Both modulators have low insertion losses and high extinction ratios.

Investigation of the diocotron instability of an infinitely wide sheet electron beam by using the macroscopic cold-fluid model theory

This paper investigates the diocotron instability of an infinitely wide relativistic sheet electron beam in conducting walls propagating through a uniform magnetic field by using the macroscopic cold-fluid model theory. Assuming low-frequency perturbations with long axial wavelengths, the eigenvalue equation and the dispersion relation are acquired for a sheet electron beam with sharp boundary profile and uniform density. The results presented in this paper has developed the use of the macroscopic cold-fluid model theory by extending the parameter of the electron cyclotron frequency ωc to a wider usage range, which is restricted to be much larger than the plasma frequency ωp in the previous research work. Theoretical analyses and numerical calculations indicate that the transport of the sheet electron beam will be completely stabilized by augmenting the normalized beam thickness to a conductor gap larger than a threshold λb, which is greatly dependent on the parameter ωc/ωp. The larger ωc/ωp is, the smaller λb will be needed. Moreover, the system parameters, including the wave number kx of the perturbations and the relativistic mass factor γb, will also influence the growth rate of diocotron instability obviously.

Diocotron instability of a relativistic sheet electron beam propagating through a rectangular conducting wall

Properties of the diocotron instability in a relativistic sheet electron beam propagating through a rectangular conducting wall are investigated within the framework of a macroscopic cold fluid model. The electron beam is assumed to be partially neutralized by the positive immobile ions with the fractional charge neutralization f. The eigenvalue equation is obtained for low-frequency perturbations in standing waves. The dispersion relation of the diocotron instability is derived and used to investigate stability properties for a broad range of system parameters including the ratio a/d of the beam thickness (2a) to the conductor gap (2d) and the charge neutralization f. The dispersion relation indicates that the system is stabilized by increasing the neutralization f to 1/γ2b, where γb is the characteristic value of the beam relativistic factor. It is also shown that the diocotron perturbations are completely stabilized by increasing the beam thickness to more than one-half the conductor gap (i.e., a/d≳0.5) for f=0. The growth rate of instability is a substantial fraction of the diocotron frequency if the system is unstable.

A Simple Technique for Investigating Defects in Coaxial Connectors (Short Paper)

This paper describes a technique that uses swept-frequency automatic network analyzer (ANA) data for investigating electrical defects in coaxial connectors. The technique will he useful to connector and ANA manufacturers and to engineers interested in determining connector characteristics for error analyses. A simplified theory is presented and the technique is illustrated by applying it to perturbations caused by the center conductor gap in a 7-mm connector pair.

Coaxial Cavities with Beam Interaction

This report considers the use of conventional center conductor gap type cavities as well as the characteristics of several other novel cavities of transverse and crossed coaxial type. The study presents electron orbits for their design and electrical parameters.

New Studies of the Transient Glow Discharge in Parallel Electrode Gaps

Studies of the parallel transmission line phase conductor gap were conducted in order to obtain a better understanding of the mechanism of lightning flashover of transmission lines. Improved techniques of digital transient recording and image converter photography were used to obtain detailed new data on the breakdown process. These data are used to evaluate models for (1) the growth of corona in the gap and for (2) the characteristics of the glow discharge phase which occurs after corona bridges the gap and before the final collapse of voltage. These models will be important for new transmission line studies, especially for those compaction studies which contemplate drastically reduced phase-phase clearances.