Energy Distribution of Periodically Dielectric Waveguides by Arbitrary Shape of Dielectric Constants — The Influence of Dielectric Structures in the Middle Layer —

2016 ◽  
Vol E99.C (7) ◽  
pp. 820-824
Author(s):  
Ryosuke OZAKI ◽  
Tsuneki YAMASAKI
Keyword(s):  
Energy Distribution ◽  
Arbitrary Shape ◽  
Middle Layer ◽  
Dielectric Constants ◽  
Dielectric Waveguides ◽  
Dielectric Structures

scholarly journals Optimization of the method for exciting an inverted strip dielectric waveguide with metal plane

2019 ◽  
Keyword(s):  
Electromagnetic Field ◽  
Insertion Loss ◽  
Dielectric Waveguide ◽  
Wave Mode ◽  
Dielectric Constants ◽  
Dielectric Waveguides ◽  
Frequency Selection ◽  
Selection Mode ◽  
Functional Units ◽  
Dielectric Structures

Background. Currently, the application of various types of dielectric waveguides in the millimeter wavelength range is very promising, including metal-dielectric structures and functional units based on them. This is due to the simplicity and low cost of manufacturing dielectric waveguides and functional units based on them, the possibility of their integration with active elements, the use of various dielectrics and polymers having both a wide range of dielectric constants and a variety of mechanical properties (in particular, some dielectric materials have significant flexibility).Objectives. To optimize the method of excitation of one of its eigenwaves in a inverted strip dielectric waveguide with a metal plane through a series of physical experiments.Materials and methods. The studied electrodynamic structure belongs to the class of hybrid metal-dielectric structures. Its basis is a inverted strip dielectric waveguide with a metal plane. A feature of the used inverted strip dielectric waveguide is its composition: the main part of the waveguide rod adjacent to the metal plane is made of polystyrene, the second part is made of fluoroplastic. The evaluation of the excitation efficiency was carried out by the magnitude of the introduced attenuation into the tract. Using the method of a moving probe, the degree of concentration of the electromagnetic field near a complex compositional waveguiding rod was estimated. The fields were visualized using the contour method.Results. Based on a series of experimental studies, the method for exciting an inverted strip dielectric waveguide with a metal plane is optimized. The effect of optimal excitation was achieved through the use of the composite design of the dielectric waveguiding rod. With the optimal ratio of the material constants of the layers forming the waveguiding rod and the geometric parameters of these layers, it was possible to significantly expand the working frequency band, within which the level of insertion loss did not exceed the specified values. It was found that the electromagnetic field is concentrated mainly near the dielectric rod, providing a stable wave mode. It has been established that with a certain ratio of structure parameters, the frequency selection mode can be implemented in it. Conclusions. In the course of physical measurements, it was found that a inverted strip dielectric waveguide with a metal plane with the optimal choice of parameters is able to effectively maintain the wave mode with a low level of insertion loss. In general, a structure with a certain choice of parameters can operate in two regimes: waveguiding mode and frequency selection mode.

Energy Distribution in Electron Beams

1972 ◽  
Vol 30 ◽  
pp. 568-569
Author(s):  
Tamotsu Ohno
Keyword(s):  
Electron Beam ◽  
Energy Distribution ◽  
Cross Section ◽  
Integral Curve ◽  
Electron Beams ◽  
Electron Gun ◽  
Angular Divergence ◽  
Apparent Increase ◽  
Integral Width ◽  
The Cross

The energy distribution in an electron; beam from an electron gun provided with a biased Wehnelt cylinder was measured by a retarding potential analyser. All the measurements were carried out with a beam of small angular divergence (<3xl0-4 rad) to eliminate the apparent increase of energy width as pointed out by Ichinokawa.The cross section of the beam from a gun with a tungsten hairpin cathode varies as shown in Fig.1a with the bias voltage Vg. The central part of the beam was analysed. An example of the integral curve as well as the energy spectrum is shown in Fig.2. The integral width of the spectrum ΔEi varies with Vg as shown in Fig.1b The width ΔEi is smaller than the Maxwellian width near the cut-off. As |Vg| is decreased, ΔEi increases beyond the Maxwellian width, reaches a maximum and then decreases. Note that the cross section of the beam enlarges with decreasing |Vg|.

Electron microscopy studies of PZT ferroelectric film capacitor structures

1992 ◽  
Vol 50 (2) ◽  
pp. 1364-1365
Author(s):  
V. Kaushik ◽  
P. Maniar ◽  
J. Olowolafe ◽  
R. Jones ◽  
A. Campbell ◽  
...  
Keyword(s):  
Electric Fields ◽  
Sol Gel ◽  
Ferroelectric Material ◽  
Dielectric Constants ◽  
Dielectric Films ◽  
Lead Zirconium Titanate ◽  
Si Substrate ◽  
Film Capacitor ◽  
Pzt Films ◽  
High Dielectric

Lead zirconium titanate films (Pb (Zr,Ti) O3 or PZT) are being considered for potential application as dielectric films in memory technology due to their high dielectric constants. PZT is a ferroelectric material which shows spontaneous polarizability, reversible under applied electric fields. We report herein some results of TEM studies on thin film capacitor structures containing PZT films with platinum-titanium electrodes.The wafers had a stacked structure consisting of PZT/Pt/Ti/SiO2/Si substrate as shown in Figure 1. Platinum acts as electrode material and titanium is used to overcome the problem of platinum adhesion to the oxide layer. The PZT (0/20/80) films were deposited using a sol-gel method and the structure was annealed at 650°C and 800°C for 30 min in an oxygen ambient. XTEM imaging was done at 200KV with the electron beam parallel to <110> zone axis of silicon.Figure 2 shows the PZT and Pt layers only, since the structure had a tendency to peel off at the Ti-Pt interface during TEM sample preparation.

The need of electron microscopy in the study of domains and domain walls in ferroelectrics

1994 ◽  
Vol 52 ◽  
pp. 550-551
Author(s):  
Wenwu Cao
Keyword(s):  
Domain Wall ◽  
Domain Walls ◽  
High Mobility ◽  
Continuum Theory ◽  
Polarization Vector ◽  
Ferroelectric Materials ◽  
Dielectric Constants ◽  
Nonlocal Coupling ◽  
Cubic Symmetry ◽  
Gradient Energy

Domain structures play a key role in determining the physical properties of ferroelectric materials. The formation of these ferroelectric domains and domain walls are determined by the intrinsic nonlinearity and the nonlocal coupling of the polarization. Analogous to soliton excitations, domain walls can have high mobility when the domain wall energy is high. The domain wall can be describes by a continuum theory owning to the long range nature of the dipole-dipole interactions in ferroelectrics. The simplest form for the Landau energy is the so called ϕ model which can be used to describe a second order phase transition from a cubic prototype,where Pi (i =1, 2, 3) are the components of polarization vector, α's are the linear and nonlinear dielectric constants. In order to take into account the nonlocal coupling, a gradient energy should be included, for cubic symmetry the gradient energy is given by,

Magnetic energy distribution in polycrystalline sputtered CoCr magnetic thin films

2008 ◽  
Vol 42 (2) ◽  
pp. 125-128
Author(s):  
J. F. Al-Sharab ◽  
J. E. Wittig ◽  
G. Bertero ◽  
T. Yamashita ◽  
J. Bentley ◽  
...  
Keyword(s):  
Thin Films ◽  
Energy Distribution ◽  
Magnetic Energy ◽  
Magnetic Thin Films
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