Ultrasonic wedges which can propagate one longitudinal L and two orthogonally polarized shear S waves are presented. In order to use this wedge to generate and received guided plate acoustic waves along a metal plate at high temperatures brass which has a slow L and S wave velocities was chosen. Mode conversion method was used to convert L to S waves in the wedge. The mode conversion efficiency...

A new metal mesh coupler that makes use of a tunneling effect of evanescent waves between a metal mesh and a dielectric plate, has been proposed as a quasi-optical component for millimeter and submillimeter wavelengths. Theoretical calculation and experimental measurement performed from 40 GHz to 60 GHz show that the transmittance of the coupler can be changed more than 50 % for the variation o...

A miniaturized internal wideband antenna suitable for integration with the printed circuit board (PCB) of a wireless universal serial bus (WUSB) dongle is presented in this paper. The proposed antenna mainly consists of a folded metal plate with two sides beveled. By introducing a short-circuited pin connected to the system ground and etching a pair of slots in the bevel sides of the folded met...

A small base isolation system using a new device that used friction force was developed. In this paper, dynamic characteristics of the system were investigated by an experiment using artificial seismic wave. The bearing combination of three cases, four spherical metal bearings, two spherical metal and two marble plate bearings, four marble plate bearings, was done in the experiment. The peak ac...

The influence of metal vapour on the arc behaviour during the arc-splitting process in the quenching chamber of a low-voltage circuit breaker is investigated numerically. A three-dimensional magnetohydrodynamic model of air arc plasma, taking into account the production of metal vapour from erosion of an iron splitter plate, is developed. An equation describing conservation of the iron vapour m...

An electromagnetic pulse (EMP) explodes in real-time and causes critical damage within a short period to not only electric devices, but also to national infrastructures. In terms of EMP shielding rooms, metal plate has been used due to its excellent shielding effectiveness (SE). However, it has difficulties in manufacturing, as the fabrication of welded parts of metal plates and the cost of con...

1. Introduction This paper proposes beam scan by moving dielectric blocks mechanically in the feed waveguide of single-layer slotted waveguide arrays as shown in Fig.1. Millimeter-wave antennas with beam scan are desired in various systems such as collision-avoidance car radars [1-3]. Electrical scanning is the best but mechanical one is still attractive in terms of cost, efficiency, heat-radia...