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A design study of a 0.1-THz coupled-cavity backward-wave oscillator (CCBWO) is presented using a finite element method and a particle-in-cell simulation. In experiments, the Si-based technology of 2-step deep reactive ion etching (DRIE) and eutectic bonding shows a good potential for the microfabrication of the interaction circuit. A miniaturized field(More)
We introduce the subwavelength transmission of an effective surface plasmon beyond the light zone via the proximity interaction of convection electrons with a metal grating. A comparative analysis of dielectric homogenization and a finite-difference-time-domain simulation shows that out-of-phase-like modes (pi modes) have strong transmission below the(More)
We investigated foundations for high frequency vacuum electron devices, experimentally with emphasis on LIGA (deep etch X-ray lithography: lithographie, galvanoformung, abformung; German acronyms) to fabricate a miniaturized interaction circuit and a photonic crystal (PC) resonator to excite a stable high order mode. The successful operation of a(More)
Metallic metamaterials with positive dielectric responses are promising as an alternative to dielectrics for the generation of Cerenkov radiation [J.-K. So et al., Appl. Phys. Lett. 97(15), 151107 (2010)]. We propose here by theoretical analysis a mechanism to couple out Cerenkov radiation from the slab surfaces in the transverse direction. The proposed(More)
We report experimental and finite-difference time-domain simulation studies on terahertz (THz) characteristics of band gaps by using metal grooves which are located inside the flare parallel-plate waveguide. The vertically localized standing-wave cavity mode (SWCM) between the upper waveguide surface and groove bottom, and the horizontally localized SWCM(More)
Generation of a sheet beam directly from a scandia-doped dispenser cathode has been investigated and optimized by means of beam-profile simulations and measurements. Rectangular beams 600 mum wide and 100 mum thick with current densities over 50 A/cm<sup>2</sup> have been generated. The beams are stable for at least several hundred hours with the cathodes(More)
Transmission of electromagnetic waves through thick perfect conducting slabs perforated by one-dimensional arrays of rectangular holes was studied experimentally in the microwave frequency range. The observed thickness-dependent transmission clearly exhibits the evanescent and propagating nature of the involved electromagnetic excitations on the considered(More)