Iris type waveguide to cavity couplers are used to couple power to particle accelerator cavities. Waveguide to cavity coupling for arbitrarily oriented rectangular iris is analyzed using Bethe’s small hole coupling theory. Magnetic moment of rotated iris is obtained by defining its dyadic magnetic polarizability. Power radiated by magnetic moment into the incoming waveguide is used for coupling...

Numerical simulations were used to design a variety of high-Q resonant cavities for integration into a terahertz 2D photonic crystal waveguide. After fabrication, the transmission characteristics of each integrated cavity were explored. These photonic waveguide-coupled cavities demonstrate resonances with linewidths approaching 10 GHz. The results compare favorably to previous observations of r...

This work presents a design technique to implement miniaturized cross-coupled bandpass filters in inline physical configurations based on triple-mode resonators. Triple-mode resonances are obtained by using integrated coaxial-waveguide cavity They consist of two coaxial conducting posts placed the sidewalls rectangular waveguide cavity. In proposed triplet, transmission zero (TZ) can be positio...

In many microwave applications, an accurate knowledge of the complex permittivity properties of materials is usually required. A new procedure for the accurate determination of these properties is presented, based on an optimization algorithm that makes use of measured scattering parameters and simulated results of a cylindrical rod of dielectric material passing completely through a rectangula...

In this paper, a design of compact coplanar waveguide fed UWB slot antenna is presented. The proposed antenna has simple structure consisting rectangular slot with uneven coplanar ground structures. The proposed antenna structure is investigated by using MoM based electromagnetic solver IE3D. The simulation and measured results show that the antenna offers performance for wideband system from 4...

In this paper we consider embedded eigenvalues of a Schrödinger Hamiltonian in a waveguide induced by a symmetric perturbation. It is shown that these eigenvalues become unstable and turn into resonances after twisting of the waveguide. The perturbative expansion of the resonance width is calculated for weakly twisted waveguides and the influence of the twist on resonances in a concrete model i...

In this study, we demonstrated a new class of frequency-switchable metamaterial absorber in the X-band. Eutectic gallium-indium (EGaIn), a liquid metal alloy, was injected in a microfluidic channel engraved on polymethyl methacrylate (PMMA) to achieve frequency switching. Numerical simulation and experimental results are presented for two cases: when the microfluidic channels are empty, and whe...

In this paper we present a simple method for efficient modeling of the tunneling effect in a non-homogeneous epsilon-near-zero (ENZ) waveguide, using an equivalent circuit approach. ENZ waveguide consists of rectangular waveguides filled with two-layered dielectric, E-step, and a narrow channel. It was shown that the E-step in a non-homogenous structure can be modeled rather simply using a shun...

Integral equation formulation and magnetic potential Green’s dyadics for multilayered rectangular waveguide are presented for modeling interacting printed antenna arrays used in waveguidebased spatial power combiners. Dyadic Green’s functions are obtained as a partial eigenfunction expansion in the form of a double series over the complete system of eigenfunctions of transverse Laplacian operat...