THE HISTORY OF SOFTWARE DEVELOPMENT AND WAVEGUIDE ELEMENT INVESTIGATIONS IN THE DEPARTAMENT OF COMPUTATIONAL ELECTROMAGNETICS OF IRE

(1970-1980)

PROGRAM TOOLS Machine codes, ALGOL-60, FORTRAN

METHODS Residue-calculus method and it’s modifications, semi-inversion of convolution-type matrix equations (with the difference in the matrix elements denominators), Generalized S-Matrix Technique (GSMT).

OBJECTS Inclined strip gratings, echelletts, metal or dielectric gratings of circular or rectangular rods, gratings with dielectric layers, polarization gratings.

Steps and bifurcations in circular and rectangular waveguides (WG)s and complicated units on them, H-plane angled bends in rectangular WGs and other 2-D discontinuities, power calorimetric loads on angled bends, H-plane dielectric interfaces.

SUBJECTS General properties, resonances and Wood’s anomalies, “locked” modes in conventional and “Floque”-waveguides, resonances within dielectric layers near gratings (including phased array coatings), conversion of WG-modes (), comparison of exact methods with heuristic ones in multimode frequency band, investigations of principles of numerical algorithm estimations and comparisons, numerical estimation of convergence and possible errors, methods of obtaining the improved numerical solutions.

(1980-1990)

PROGRAM TOOLS FORTRAN, PL-1

METHODS Semi-inversion of convolution-type matrix equations, mode-matching technique, GSMT, moment methods, integral equations, Rieman-Hilbert problem of the theory of analytical functions, residue-calculus method and it’s modifications, Wiener-Hopf technique and method of the Weber-Schafheitlien’s integral for opened WGs.

S-matrix tecniques based systematical approach to waveguide device modeling as the global goal of scientific group.

OBJECTS SES-04 as the problem-oriented tool for electromagnetic investigations of the structures with discrete spatial spectrum (more 30 key-building elements) and for approbations of the ideas, appearing at the system creation, as themselves;

E- and H-plane noncoordinate discontinuities in rectangular WGs, bandpass and bandstop millimeter wave filters, diplexers and multiplexers;

Reflecting gratings: echelletts, lamellar gratings, strip gratings on dielectric substrate and the screen.

Gratings, slow-wave structures and waveguide devices as open resonators loaded on waveguides with the discrete spatial spectrum;

Open resonators with dispersive mirrors, waveguide modeling of open resonators.

SUBJECTS General properties of the eigen frequency spectra of open WG resonators; complex frequency spectra of bends, widenings, tees, waveguide-dielectric resonators, complicated WG devices and different periodical structures.

Nonmirror reflection of waves from gratings for open resonator’s and antenna applications;

Coordinate metal and dielectric resonators in circular waveguides;

A variety of SES-04 applications for scientific and technical purposes.

(1990 - up to the present)

PROGRAM TOOLS PL-1, C++

METHODS.....(see above) plus the methods, based on special bases in moment method, the stepped approximation of smooth boundaries corrected for the location of “equivalent reflection surfaces”, LSE-LSM scalarization technique for some of 3-D problems, transverse resonant method for waveguides with complicated cross-sections and generalized mode-matching technique for their junctions, minimax problems, method of repeated shorts for reducing the order of multiport problems, wide using interpolation models and buffering at optimization of device geometry, further extension of used techniques at calculation of coupling integrals in mode-matching technique.

OBJECTS C++ classes based compiler and the libraries (SES-tools) for SES-06 including functional key-blocks in addition to conventional structural key-elements.

Open resonators with echelette and corner-echelette mirrors.

Lowpass, bandpass and bandstop filters of various configurations; diplexers and multiplexers of various types; multisectional circular-to-rectangular w/g transitions, pillbox-type vacuum windows for satellite applications, dual-mode filters (4-1, 6-1, 8-1 and 8-2), lowpass and bandpass filters on ridge WG sections.

SUBJECTS Reconstruction of S-matrixes on the complex frequency spectrums, new explanation of typical resonance phenomena. Regular calculations of the spectral passports of the main waveguide elements.

The creation of initial library of key-building blocks for the new SES, the development of principles of the new SES building, realization of the kernel of the first SES-06 version.

Investigation of the spectra of echelette and corner-echelette open resonator natural oscillations.

The variety of problem-oriented softwares for CAD and CAE of microwave and millimeter wave passive devices: filters, diplexers, multiplexers, dividers, mode-converters, orthomode-transducers, matched transitions etc.

Development of standard interfaces for CAE of filters and diplexers