The desire to reduce the amount of low-loss, circularwaveguide delay line required in a pulse-compressing power distribution system for the Next Linear Collider has led to the pursuit of multi-moded schemes [1]. In such a system, power is delivered to different destinations through the same waveguide via different propagating modes. Current plans [2] utilize two modes, with manipulations done p...

Metamaterial structures have unique properties in controlling the propagation of electromagnetic waves. In this work, we analyze the effect of artificial magnetic conductor (AMC) surface strips on the bottom face of an oversized parallel plate waveguide to enhance the wave guidance within it. The results using these configurations in a linear slot array antenna fed by a rectangular parallel pla...

Digital waveguide mesh has emerged as an efficient and straightforward way to model small room impulse response because it solves the wave equation directly in the time domain. In this paper, we investigate the performance of the 3-D rectangular digital waveguide mesh in modeling the low frequency portion of room impulse response. We find that it has similar performance compared to the popular ...

The characteristics of guided waves scattered by nonuniform Bragg waveguide gratings are systematically investigated by using a staircase approximation, which is a combination of the building blocks of the multimode network theory and a rigorous mode-matching procedure. The bent dielectric waveguides, periodically with Bragg gratings of rectangular profile and chirped waveguide gratings, are ta...

We study quantum optical properties of a dipole emitter coupled to a rectangular nanoscale waveguide with dielectric core and silver cladding. We investigate enhanced spontaneous emission and the photonic Lamb shift for emitters whose resonant frequencies are near the waveguide frequency cutoff where the waveguide behaves as an ɛ-near-zero metamaterial. Via a dyadic Green's function-based field...

Abstract— This work investigates the improvement of the active reflection coefficient of waveguide-fed phased-array antenna using liquid crystal layers. The anisotropy properties of liquid crystal layer can be employed to eliminate blind scan angle and improve the wide angle impedance matching of the waveguide-fed phased array antennas. The authors have expressed the modal analysis of the waveg...

We report on the design, fabrication, and characterization of a novel 90° waveguide step twist with 56% fractional bandwidth. The proposed provides field rotation in frequency range 210–375 GHz. experimental results are good agreement electromagnetic simulations showing an insertion loss below 0.3 dB return better than 20 over most band. ultra-wideband performance, tolerance to fabrication inac...