scholarly journals Analyses of a Dipole Antenna Loaded by a Cylindrical Shell of Double Negative (DNG) Metamaterial

2007 ◽  
Vol 2007 ◽  
pp. 1-10 ◽  
Author(s):  
Khan M. Z. Shams ◽  
Mohammod Ali
Keyword(s):  
Cylindrical Shell ◽  
Input Impedance ◽  
Dipole Antenna ◽  
Double Negative ◽  
Beam Splitting ◽  
Thin Cylindrical Shell ◽  
Half Wavelength ◽  
Antenna Length ◽  
Galerkin Formulation ◽  
Parameter Values

The current distribution, input impedance, and radiation pattern of a cylindrical dipole antenna enclosed by a thin cylindrical shell of double negative (DNG) metamaterial are computed using the piecewise sinusoidal Galerkin formulation. In the presence of the DNG shell, the dipole antenna exhibits three interesting characteristics. The input impedance shows potentials for wide bandwidth due to the relative insensitivity of the impedance with frequency. Within specific ranges of DNG material parameter values, the dipole shows resonance at much lower frequencies than its resonant frequency in free space. The dipole does not show change in the direction of the principal beam nor does it show signs of beam splitting and side lobes even when the antenna length approaches one and a half wavelength.

Study on Static Assembly Interference Pressure between a Thin-Wall Flexible Cup and a Hollow Flexible Shaft

2011 ◽  
Vol 179-180 ◽  
pp. 212-219
Author(s):  
Guo Ping Wang ◽  
Hua Ling Chen ◽  
She Miao Qi ◽  
Jiu Hui Wu ◽  
Lie Yu
Keyword(s):  
Cylindrical Shell ◽  
Pressure Distribution ◽  
Superposition Principle ◽  
Special Solution ◽  
Thin Wall ◽  
Thin Cylindrical Shell ◽  
Bending Deformation ◽  
Flexible Shaft ◽  
First Time ◽  
Thin Shell Theory

Distribution of static interference pressure between a thin-wall flexible cup and a flexible shaft fluctuates heavily along the axis of the cup and is quite different from pressure distribution of common interference styles. In this article, aiming at solving distribution of static interference pressure between a thin-wall flexible cup with much thicker bottom and a hollow flexible shaft, mechanical model and mathematical model of solving the problem were built based on classic thin shell theory. Special difference is that precise special solution of bending equation of thin cylindrical shell was used to substitute the special solution which is original from bending deformation of thin cylindrical shell in no moment status. And a brand new general solution, the relational expression between bending deformation of thin wall of the cup and distribution of the static interference pressure, was obtained. Then, a method used to solve the pressure distribution was presented by solving integral equation and applying superposition principle for the first time. Through using the method to solve an example and comparing calculated results with FEM results, it was proved that the method is correct and effective.

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