Arrays of dielectric resonators—illuminated by an antenna—are used to ignite and sustain multiple microwave plasmas in parallel. Calcium titanate cylindrical resonators were arranged in a linear array with separation distances between 0.5 and 5 mm. The operating frequency was near the HEM111 resonance of 1.1 GHz. Paschen curves of the breakdown field and voltage in argon atmosphere are consiste...

We demonstrate effectively two-dimensional (2D) terahertz (THz) photonic bandgap (PBG) structures for transverse electromagnetic (TEM) mode propagation within metal parallel plate waveguides (PPWG). The 2D-PBG structures consisting of square arrays of dielectric cylinders were characterized by THz time-domain spectroscopy (THz-TDS). THz photonic bandgaps were observed, as determined by the 160 ...

Electromagnetic coupling between two aperture antennas in the shape of the open ends of parallel-plate waveguides located on the same metal surface has been analyzed. The design optimization of the surface impedance model is used to solve this problem. The required level of antenna decoupling is obtained taking into account the initial metal surface, which is a natural decoupling structure. The...

ATLAS has chosen for its Hadronic End-Cap Calorimeter (HEC) the copper-liquid argon sampling technique with flat plate geometry and GaAs pre-amplifiers in the argon. The contruction of the calorimeter is now approaching completion. Results of production quality checks are reported and their anticipated impact on calorimeter performance discussed. Selected results, such as linearity, electron an...

A metallic photonic crystal filter has been demonstrated at terahertz frequencies, with the passband tuneable over the range 365 386 GHz. Tuning is achieved by a relative lateral shift of two metallic photonic crystal plates. Each plate comprises two orthogonal layers of gratings and integral mounting lugs. The plates are micromachined from silicon wafers then coated in gold to provide metallic...

An overview of the current state of the art in scanning micromirror technology for switching, imaging, and beam steering applications is presented. The requirements that drive the design and fabrication technology are covered. Electrostatic, electromagnetic, and magnetic actuation techniques are discussed as well as the motivation toward combdrive configurations from parallel plate configuratio...

A complete landscape is presented of the acoustic transmission properties of subwavelength apertures (slits and holes). First, we study the emergence of Fabry-Perot resonances in single apertures. When these apertures are placed in a periodic fashion, a new type of transmission resonance appears in the spectrum. We demonstrate that this resonance stems from the excitation of an acoustic guided ...

A micromachined loudspeaker for audible acoustic instruments is designed, fabricated and tested. A single loop voice coil on a flexible polyimide membrane is conceived to serve as the sound generating plate, and is driven by electromagnetic actuation. The diameter of the microspeaker is 5 mm × 5 mm, and it is fabricated by a low temperature micromachining process. At a driving voltage of as low...

This paper proposes a new cross-hole tomography imaging (CTI) method for variable-depth defects in metal plates based on multi-mode electromagnetic ultrasonic Lamb waves (LWs). The dispersion characteristics determine that different modes of LWs are sensitive to different thicknesses of metal plates. In this work, the sensitivities to thickness variation of A0- and S0-mode LWs are theoretically...

the effect of a distributed patch mass on the natural frequency of vibration of a laminated rectangular plate with simply supported boundaries is investigated. the third order displacement field of a composite laminated rectangular plate is defined using the two variable refined plate theory. equations of motion of the plate are obtained with the help of calculus of variation. parametric study ...