Protap Pramanick

Stripline Transition to Ridge Waveguide Bandpass Filters

Full wave optimization is implemented to design a wide band transition from shielded stripline to ridge waveguide. A bandpass ridge waveguide filter, with input/output realized through tapped-in stripline is designed. Using rigorous mode matching technique the generalized scattering matrices of all the building blocks are obtained. Design procedure is described and examples are given to demonstrate the features of the tapped-in coupling structure. The tapped-in structure results in a considerable reduction of the filters total length compared to the use of two transitions.

Dispersion characteristics of square pulse with finite rise time in single, tapered, and coupled microstrip lines

The distortion of an electrical pulse, with finite risetime (quadratic-linear-quadratic transition) caused by dispersion as it propagates along a uniform microstrip, a tapered microstrip and a coupled pair of microstrips is investigated. Closed-form analysis equations for single and coupled microstrips are used to find the frequency-dependent phase velocities. Results are presented for two different taper profiles: exponential and triangular distributions. It is concluded that the optimization of the profile will provide the least pulse distortion. >

Electromagnetic modeling of multi-layer microwave circuits by the longitudinal decomposition approach

A system approach based on the transverse-resonance technique and well-equipped modeling system is used to calculate the eigen-mode spectrum of multiconductor lines with piece-wise continuous coordinate boundaries of their cross-section. The exact models of the multi-layer circuits are built with the mode-matching and generalized S-matrix techniques. Viability of the created program tools is demonstrated with the examples of a multi-turn loop inductor and a third-order low-pass filter.

Frequency dependence of equivalent dielectric constant in finlines

This paper develops a simple but accurate LSE model for accurate prediction of phase velocity in fin-lines. The model is general and equally applicable to unilateral, bilateral and insulated fin-lines. Closed-form expressions, derived from the model, give the phase velocity within to ±0.8 percent of sophisticated numerical techniques.

Computer Aided Design Models for Unilateral Finlines with Finite Metallization Thickness and Arbitrarily Located Slot Widths

This paper presents closed form design equations for the phase constant of unilateral finlines with finite metallization thickness and arbitrarily located slots. The equations are based on numerical data obtained using the highly accurate conservation of complex power technique.

A Generalized Theory of Tapered Transmission Line Matching Transformers and Asymmetric 180° Couplers Supporting Non-TEM Modes

This paper presents a generalized Fourier transform pair for the analysis and synthesis of tapered transmission lines supporting a non-TEM mode. The Fourier transform pair first pointed out by Bolinder, and subsequently used by Klopfenstein for TEM lines can be shown to be a special case of the present transform pair. A step by step synthesis method has been described for exact designs of matching transformers and asymmetric 180° directional couplers.

STRIPLINE TRANSITION TO RIDGE WAVEGUIDE BANDPASS FILTERS - Abstract

Full wave optimization is implemented to design a wide band transition from shielded stripline to ridge waveguide. A bandpass ridge waveguide filter, with input/output realized through tapped-in stripline is designed. Using rigorous mode matching technique the generalized scattering matrices of all the building blocks are obtained. Design procedure is described and examples are given to demonstrate the features of the tapped-in coupling structure. The tapped-in structure results in a considerable reduction of the filters total length compared to the use of two transitions.

Decomposition approach to multilayer circuits electromagnetic modeling

A system approach based on the transverse resonance technique and a well-equipped modeling system is used to calculate the eigen-mode spectrum of the multiconductor lines with the piecewise coordinate boundary of cross-section. It serves as the background for calculation of the multilayer circuit frequency response by mode-matching and S-matrix techniques.

Optimization of waveguide diplexers using shadow specifications

This paper uses a new optimization technique for determining the frequency response of waveguide diplexers. The proposed technique is considerably more advantageous than the conventional waveguide filter optimization techniques. The technique uses only six variables in the penalty function irrespective of the orders of the two channel filters. This drastically reduces the chances of convergence to a local minimum as well as the computer storage and processing requirements. Two examples are presented to support the validity of this new technique. This technique will be extremely valuable in designing waveguide multiplexers.

Analysis of microstrip step discontinuity on uniaxially anisotropic substrate

The scattering parameters of a step discontinuity in a microstrip line, on an uniaxially anisotropic substrate, has been analyzed using the mode matching technique. Closed-form equations for the dispersion of the effective dielectric constant and the effective width of the planar waveguide model of microstrip on an anisotropic substrate have been used. Computed data are presented for a number of commercially available anisotropic substrates, for different cutting angles.<<ETX>>