Pradip Kumar Saha

Rectangular Waveguide with T-Shaped Septa

Recently, a new rectangular waveguide with two T-shaped septa has heen proposed by the authors as a superior alternative to conventional ridged guide. Here, numerical data on the cutoff and band-width characteristics of the dominant TE/sub 10/ mode of rectangular waveguide with a single T-septum are presented and compared with those of single-ridged guides. The gap impedances of both the double and single T-septum guides are also determined as functions of gap parameters.

A Novel Rectangular Waveguide with Double T-Septums (Short Paper)

A new rectangular waveguide with two T-shaped septums in place of solid rectangular ridges has been analyzed theoretically by the Ritz-Galerkin technique and is found to have superior cutoff and bandwidth characteristics of the dominant TE/sub10/ mode compared to the conventional ridged guides. Numerical data are presented and compared with those of symmetric double-ridged guides with identical gap parameters.

New broadband rectangular waveguide with L-shaped septa

Broadband septum waveguides that are a variant of the previously reported double T-septa guide (DTSGs) are proposed. These guides have L-shaped septa located antisymmetrically and are called double L-septa guides (DLSG). The authors present the theoretical cutoff and bandwidth characteristics of the dominant TE modes of the DLSG, compare them with those of DTSG, and examine the effect of partial overlapping of septa. Results indicate that significant improvement in cutoff wavelength and bandwidth in particular should be available with L-shaped septa in antisymmetric configuration. >

Bandwidth characteristics of inhomogeneous T-septum waveguides

Rectangular waveguides with T-shaped septa were recently shown to have superior characteristics compared to conventional ridged guides. Here, the dispersion equations of the hybrid modes of an inhomogeneously filled septum guide are determined by the Ritz-Galerkin technique. Results of numerical computations indicate that with dielectric filling of the septum gap, further enhancement of the cutoff wavelength of the lowest mode and the bandwidth with respect to the next higher mode is possible. >

Some characteristics of ridge-trough waveguide

A single-ridged waveguide with a symmetrical longitudinal trough below the ridge, designated as a ridge-trough waveguide (RTW) has been recently proposed as a wafer probe. The authors have theoretically calculated the cutoff, bandwidth, and impedance characteristics of this modified single-ridged waveguide in two different configurations using the Ritz-Galerkin technique and different domain decompositions. The results indicate that a RTW can be a low impedance broad-band structure.

Study of bound surface plasmon modes on subwavelength structures of rectangular cross section using a simple analytical technique

Propagation characteristics of surface plasmon polariton (SPP) modes supported by subwavelength guiding structures of rectangular cross section have been determined through matching of trial field solutions on the boundary. Two complementary structures are solved using the same formulation: a metal wire embedded in a dielectric and an aperture in a metal film. Though simple and approximate, the method yields results that show good agreement with the published results obtained by numerical methods.

Characteristics of inhomogeneously filled double L-septa waveguides

Three types of inhomogeneous double L-septa guide (DLSG) produced by selective dielectric loading of the different regions are analyzed. The cutoff and bandwidth characteristics of these configurations are compared with the inhomogeneous T-septa guide and homogeneous DLSG. An optimum configuration with very large bandwidth emerges as a potential structure for practical implementation. >

Computation of surface plasmon modes in prism-buffer layer-metal configuration using a method of lines modeling scheme

Dispersion of propagation constants of Surface Plasmon Polariton (SPP) modes at a metal-dielectric interface with the thickness of buffer layer in Otto configuration is modeled using Method of Lines (MOL). The model is validated with published results for modified Otto configuration with multilayered buffer dielectric.

Impedance, attenuation and power-handling characteristics of double L-septa waveguides

Rectangular waveguides with two L-shaped septa attached to the broad walls in antipodal configuration have been shown theoretically by the authors (see ibid. vol.40, no.4, p.777-781, 1992) to be an improved variant of the double T-septa guide having larger cut-off wavelength and broader bandwidth of the dominant TE mode. Numerical data on the attenuation, impedance, and power handling capability of this new type of broadband guide are presented as additional design information. >

Dispersion characteristics of unilateral and bilateral fin lines by the Ritz-Galerkin technique

The Ritz–Galerkin technique is applied without any approximation in the formulation of the problem to determine the dispersion characteristics of hybrid modes in unilateral and bilateral fin lines with finite metallization thickness and substrate holding grooves in the waveguide housing. The characteristics calculated by this method are the dominant and higher mode dispersion, the monomode bandwidth and the effective permittivity as functions of various fin line parameters. These are compared with some recently published results and are found to be in good agreement.