The theoretical study outlined in this paper is motivated by the growing interest in microwave imaging in closed microwave systems. We present an original approach to the inverse problem of reconstruction of media parameters (complex permittivity) of a body in a waveguide. The consideration is based on the use of a volume singular integral equation and its reduction to an equation which can be ...

This dissertation focuses on designing, fabricating and testing antennas that are suitable for operation within the V/W bands. In particular, this work focuses on the design of slotted rectangular waveguide antenna arrays and cross slotted waveguide fed horn antennas. These structures are known for their high efficiency and high circularly polarized gain that can be implemented in satellite and...

In this paper, an electromagnetic analysis is presented for describing the influence of shielding in a rectangular waveguide. A hybridization based on the method of moments combined to the generalized equivalent circuit MoM-GEC is used to model the problem. This is validated by applying the MoM-GEC hybridization to investigate a diffraction structure. It consists of electromagnetic diffraction ...

A semi-analytical method to analyze post-wall waveguides and circuits based on the model of two-dimensional photonic crystals formed by layered periodic arrays of circular cylinders is presented. The propagation constant of the fundamental TE mode, the attenuation constant due to the leakage loss and the effective width of an equivalent rectangular waveguide are calculated. Using the concept of...

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, ...

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.