Extremely small aperture radial line slot antennas (RLSAs) are analyzed by method of moments. At first, the analysis model of cylindrical waveguide in terms of rectangular cavity modes is confirmed for a RLSA with a spiral slot arrangement. The overall VSWR as well as rotational symmetry of the actual structure of RLSAs is predicted for the first time and is confirmed experimentally. Secondly, ...

We consider theoretically two coupled optical waveguides with a varying barrier height along the waveguides direction. The barrier could be constructed by the elongated island with a reduced refractive index (which acts as a potential barrier), such that in the middle region it splits a waveguide into two weakly coupled parts. It is predicted by numerical simulations and analytical consideratio...

ince many applications rely on the knowledge of the electromagnetic material properties of ferrites, such as ferrite phase shifters, this paper presents an algorithm for characterizing ferrite materials in a single frequency using a rectangular waveguide system. In this method, the extraction of ferrite parameters is implemented through minimizing the difference between the measured data and th...

In this paper, scattering and coupling problems of the directional coupler for the dielectric rectangular waveguides are analyzed by the mode-matching method in the sense of least squares for the fundamental mode incidence. This directional coupler is composed of three parallel dielectric rectangular waveguides cores which are placed at equal space in the dielectric medium. Namely, respective c...

1. Introduction A leaky-wave line-source antenna is basically an open waveguide that supports a leaky mode (instead of a bound mode) and that therefore radiates all along its length. For use at millimeter wavelengths, various novel leaky-wave antennas were proposed, analyzed, and measured based on some low loss open waveguide designed specifically. Since these waveguides are already open, a phy...

A full-wave electromagnetic model is developed and verified for a waveguide transition consisting of slotted rectangular waveguides coupled to a strip line. This waveguide-based structure represents a portion of the planar spatial power combining amplifier array. The electromagnetic simulator is developed to analyze the stripline-to-slot transitions operating in a waveguidebased environment in ...

In this paper, the full-wave analysis and experimental verification of a waveguide-based aperture-coupled patch amplifier array are presented. The spatial power-combining amplifier array is modeled by the decomposition of the entire system into several electromagnetically coupled modules. This includes a method of moments integral equation formulation of the generalized scattering matrix (GSM) ...

In this paper, we have given the scalar modes and discussed the coupling characteristics of an eight-port waveguide coupler consisting of four parallel single-mode waveguides. The analysis is based on a rectangular waveguide model which has been known to give accurate results in the case of two waveguide directional couplers. A classification of its various scalar modes is also given.

Splashplate feeds, e.g. [1], are increasingly used for high performance parabolic antennas. The feed is directly interfaced in the focus of the antenna by a straight circular waveguide through the antenna vertex which simultaneously acts as feed support. At the far side of the waveguide, the need of a circularto-rectangular waveguide transition is obvious to overcome proper interfacing with sta...