COMPUTATIONAL ELECTROMAGNETICS AND RADAR TECHNOLOGY

ARCON has maintained a strong capability in the field of Electromagnetic analysis, modeling and simulation for over 29 years. Some examples of our expertise are given in the following partial listing of our technical activities;

• Radar system design modification for improving the accuracy of ground based radar cross section measurements of low-observable targets;
• Intelligent adaptation of radar background measurements using neural networks and an expert system to optimize background subtraction under dynamic environmental conditions;
• Neural network and genetic algorithm solutions for aspects of phased array antenna control and processing (pattern synthesis, direction-finding);
• The use of visualization and computer aided design (CAD) techniques in conjunction with electromagnetic analysis computer programs;
• Application of inverse scattering theory in the development of signal processing techniques to formulate a computerized microwave imaging algorithm for real-time SAR imaging;
• Antenna modeling and simulation to model the effects of a wide variety of antenna element and system degradations and failures;
• Employing nonlinear and magnetic coupling of junctions for coherent teraHertz radiation sources...
• Design of steerable beams using JJ arrays as sub-arrays for a composite phased array for potential applications such as: teraHertz phased arrays, high frequency microwave amplifiers, portable microwave spectrometer, re- configurable ultra-wideband backbones for satellite arrays, space-space surveillance and debris detection, secured communications and imaging radar.
• Co-invention and development of a novel configuration of triangular Josephson junction array as teraHertz (sub-mm) microwave radiation device; studies of coupled arrays of large and small Josephson junctions; Formulation and use of Genetic Algorithms (GA) for the optimization of junction parameters.
• Modeling of the power-handling capabilities of high-temperature superconducting (HTS) YBCO thin films as passive microwave filters
• Development of a menu-driven user interface code for the creation of wire-grid models;
• Gain maximization of linear dipole arrays;
• Analysis of impact of inter-element coupling in antenna arrays for minimization of mutual coupling;
• Electromagnetic propagation using multiple grids with unequal periodicities;
• Development of techniques for the real time implementation of simultaneous, complementary clutter in moving radar systems;
• Development of radar signal simulation and tactical radar design software;
• Development of ray-tracing models for calculating bistatic radar cross sections of foliage covered terrain;
• Computation of ground scattering properties of monostatic and bistatic radar systems;
• Determination of the electrical and radiation characteristics of sleeve monopole antenna elements;
• Analysis and programming of cavity backed slot array antennas using dyadic Green's functions and Poisson summation methods;
• Development and application of mathematical analysis and computational techniques to the numerical solution of integral and integro-differential equations related to such topics as; a) scattering by electrically small, medium, and large objects; electrical and scan characteristics of cavity-backed slot arrays; b) ground-wave propagation c) determination of electric field interactions among parallel conducting strips on planar arrays.

Representative Publications List:

Lin, F. C., and M. A. Fiddy, "The Born-Rytov controversy: II. Applications to nonlinear and stochastic scattering problems in one-dimensional half-space media," J. Soc. Opt. Am., A10, 1971-1983, 1993.

Lin, F. C., and M.A. Fiddy, "The Born-Rytov controversy: I. Comparing analytical and approximate expressions for the one-dimensional deterministic case," J. Soc. Opt. Am., A9, 1102-1110, 1992.

Lin, F. C., and M. A. Fiddy, "Image estimation from scattered field data," International Journal of Imaging Systems and Technology, 2, 76-95, 1990.

Morris, J. B., F. C. Lin, D. A. Pommet, R. V. McGahan, and M. A. Fiddy, "A homomorphic filtering method for imaging strongly scattering penetrable objects," IEEE Ant. Propagat., 43, 1029-1035, 1995.

Cohen, E., "An Ewald Transformation of Frequency Domain Integral Formulations", Electromagnetics, 15,(4), pp. 427-439, July 1995.

Tomasic, B. and Cohen, E., "Sleeved Monopole Arrays", IEEE Antennas and Propagation Soc. Int'l. Symposium, Seattle, Vol. I, pp. 502-504, 1994.

Cohen, E., "Critical Distance for Grating Lobe Series," IEEE, AP-39, No. 5, May 1991, pp. 677-679.

Mailloux, R. J., and Cohen, E., "Statistically Thinned Arrays With Quantized Element Weights, " IEEE AP-39, No. 4, April 1991, pp.436-447.

Cohen, E., Sethares, J., "MSSW Back Reaction on a Generating Current Strip," Poster Session of International Conference on Magnetism, Aug. 1985, Journal of Magnetism and Magnetic Materials, MMM5PL04, 1986, pp. 545-547.

Szabo, T. L., and Cohen, E., "Shear wave frequency-steered beams from electrode arrays", IEEE Trans. Sonics and Ultrasonics, Nov. 1983, pp. 340-345.
Sethares, J., Cohen, E., "Current Distributions on Gratings and Meanderlines: with MSW Applications", IEEE Trans. Magnetics, Vol. MAG-18, Nov. 1982, pp.1613-1615.

Cohen, E., "Surface Charge on an Unapodized Periodic IDT Having J Electrodes", IEEE Trans. Sonics and Ultrasonics, SU-27, No. 4, 1979, pp. 214-218.

Szabo, T. L., Laker, K. R., Cohen, E., "Interdigital Transducer Models: Their Impact on Filter Synthesis", IEEE Trans. Sonics and Ultrasonics, SU-26, No. 5 1979, pp. 321-333.

Laker, K. R., Cohen, E., Szabo, T. L., and Pustaver, J. A., "Computer-Aided Design of Withdrawal Weighted SAW Bandpass Filters", IEEE Trans. Circuits and Systems, CAS-25, 1978, pp. 241-251.

Laker, K. R., Cohen, E., and Slobodnik, A. J. (Jr.), "Electric Field Interactions within Finite Arrays and the Design of Withdrawal Weighted SAW Filters at Fundamental and Higher Harmonics", 1976 IEEE Ultrasonics Symposium Proc., IEEE Cat. No. 76CH 1120554, pp. 317-321.<

>Szabo, T. L., Laker, K. R., and Cohen, E., "Accurate IDT Design Using Spectral Weighting", 1976 IEEE Ultrasonics Symposium Proc., pp. 543-546. Joseph, R. A., "Visualization Toolkit for Computational Electromagnetics", 11th Annual Review of Progress in Applied Computational Electromagnetics, March 1995, pp 151-154.

Joseph, R. A., A. Paboojian, S. Woolf, and E. Cohen, "Graphical User Interface for Computational Electromagnetics Software", 13th Annual Review of Progress in Applied Computational Electromagnetics, March 1997, pp 1149ff.

Yukon, S. and N. C. Lin, "Application of Genetic Algorithms for the design of Josephson junction arrays as radiation sources", Progress in Electromagnetics Research Symposium (PIERS'97), Cambridge, MA, July 1997.

Yukon, S. and N. C. Lin, "Generation of mode-locked pulses using 2D triangular Josephson junction arrays", IEEE Trans. Appl. Sup., June 1997.
Yukon, S. and N. C. Lin, "Dynamics of Josephson junction triangle and triangular array oscillators", in "Macroscopic Quantum Phenomena and Coherence in Superconducting Networks", Proceedings of the International Conference, Frascati, Italy, March 1995, 351-359 World Scientific, Nov. 1995.

Yukon, S. and N. C. Lin, "Dynamics of triangular and tetrahedral Josephson junction oscillator arrays", IEEE Trans. Appl. Sup., 5,2959,June 1995.

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