A dual frequency and dual circular polarisation multilayer microstrip antenna element for satellite communication is presented. The element is fed by a gap-coupled probe pin. The microstrip element exhibits a dual frequency band of operation for two orthogonal circular polarisations. A parametric study to optimise the element performance has been conducted. A prototype with dimensions that are ...

The Friction Stir Welding process is now 20 years old and the interest in it and its potential continues to increase dramatically. FSW can be applied to a multitude of products with varying material types and thicknesses. However, a continuous weld is not always required to meet the product performance requirements. Thus, one can consider some form of intermittent weld, such as Friction Stir Sp...

The interaction of thermal radiation with conduction and laminar natural convection in a vertical circular pin, situated at participating gas, is numerically investigated. An absorbing and emitting gas is considered, and treated to be a gray participating media. Under the idealizing of gray gas, the Rosselan4 approximation is employed to describe the radiative heat flux in the energy equation. ...

Polarization control of electromagnetic wave is very important in many fields. Here, we propose an active meta-mirror to dynamically manipulate electromagnetic polarization state at a broad band. This meta-mirror is composed of a double-layered metallic pattern backed by a metallic flat plate, and the active elements of PIN diodes are integrated into the meta-atom to control the reflection phas...

In this work, effects of different tool pin profiles of flat and tapered shoulder geometries on the peak temperature in friction stir welding are investigated analytically. The developed models used for the analytical investigations considered the welding process as a combination or mixture of the pure sliding and the pure sticking. From the results, the amount of heat generation and the peak t...

To optimize the tool geometry (Pin profile) and process parameters for the FSW process. In the present investigation, an attempt has been made to understand the effect of rotational speed, welding speed and there different pin profiles on the nugget zone formation in AA 6063-T4 aluminum alloy. Three different tool pin profiles (tapered cylindrical, tapered square and square) have been used to f...

The interaction of thermal radiation with conduction and laminar natural convection in a vertical circular pin, situated at participating gas, is numerically investigated. An absorbing and emitting gas is considered, and treated to be a gray participating media. Under the idealizing of gray gas, the Rosselan4 approximation is employed to describe the radiative heat flux in the energy equation. ...

w w w . i j e c t . o r g InternatIonal Journal of electronIcs & communIcatIon technology 71 Abstract One of the advantages of microstrip patches over conventional antennas is their small size. However, there are many present day applications where even these small radiators are too large. A microstrip antenna incorporated with a single shorting pin is found to provide reduction in overall area...

in this study, the effects of linear and rotational speed of the friction stir welding tool was investigated on the heat generation and distribution at surface and inside of workpiece, material flow and geometry of the welding area of poly methyl methacrylate (pmma) workpiece. the commercial cfd fluent 6.4 software was used to simulation of the process with computational fluid dynamic technique...