Riley douglas j (9 Ergebnisse)

Wraps. Zustand: Fair. Reprint/Xerox type copy. Pagination is 18 pages and 12 pages of figures. List of Figures. Illustrations. Formulae. References. Appendix A and B. Printed single sided. Stapled at upper left corner. The authors were with the Radiation and Electromagnetic Analysis Division of Sandia National Laboratories in Albuquerque, New Mexico. We believe that this is the same Douglas Riley who wrote Finite Element Analysis of Antennas and Arrays. There is a notation at the top of the title page that this article was to appear in December, IEEE Trans. Ant. & Prop. [It did appear in IEEE Transactions on Antennas and Propagation ( Volume: 38 , Issue: 12 , Dec 1990).] First page is wrinkled with edge tears. A technique to incorporate a half-space aperture integral equation into a finite-difference time-domain (FDTD) code based on the offset Yee mesh (see K.S. Yee, ibid., vol. AP-14, p.302-7, 1966) is presented. To introduce the technique, linear apertures that are electrically narrow in both width and depth are discussed. The method incorporates an independent time-marching solution for the aperture problem into the FDTD code so that the aperture formally does not exist within the main FDTD mesh. A feedback scheme is introduced so that full exterior and interior coupling is included in the aperture solution. The technique is particularly useful for the analysis of apertures that are narrow both in width and depth with regard to the FDTD spatial cell. Previous thin-slot methods are shown to significantly underestimate the transverse gap electric field for this case, and an explanation for this is provided with the aid of the hybrid algorithm.…

Wraps. Zustand: Good. Reprint/Xerox type copy. Pagination is 3/4 through 40 pages. List of Figures. Illustrations. Formulae. References. Appendix A and B. Printed single sided. Stapled at upper left corner. The authors were with the Radiation and Electromagnetic Analysis Division of Sandia National Laboratories in Albuquerque, New Mexico. We believe that this is the same Douglas Riley who wrote Finite Element Analysis of Antennas and Arrays. Sub-gridding techniques enable finite-difference time-domain (FDTD) electromagnetic codes to model apertures that are much narrower than the spatial resolution of the FDTD mesh. Previous thin-slot methods have assumed that the slot walls are perfectly conducting. As the slot depth-to-width ratio becomes large, interior wall losses for realistic materials can significantly affect the coupling through the slot, and therefore these loss effects should not be neglected. This paper presents two methods for incorporating loss for walls with good, but not perfect conductivity, into the FDTD calculations. The first method modifies an FDTD equation internal to the slot to include a surface-impedance contribution. This method is appropriate for the usual FDTD thin-slot formalisms. The second method includes the losses into a "half-space'' integral equation that can be used by the recent Hybrid Thin-Slot Algorithm. Results based on the two methods are compared for a variety of slot parameters & wall conductivities.…

Zustand: New. This is a Brand-new US Edition. This Item may be shipped from US or any other country as we have multiple locations worldwide.

Zustand: Used. pp. 431.

Zustand: Used. pp. 431.

Hardcover. Zustand: Brand New. illustrated edition. 436 pages. 9.30x6.10x1.10 inches. In Stock.

Wraps. 163 p. Includes illustrations. Figures. References. SAND90-0519. Finite-difference Time-Domain (FDTD)codes can, in principle, be used to determine the electromagnetic response of complex scatters. Very good. No dust jacket as issued.

Buch. Zustand: Neu. Neuware - The Most Complete, Up-to-Date Coverage of the Finite Element Analysis and Modeling of Antennas and Arrays Aimed at researchers as well as practical engineers-and packed with over 200 illustrations including twenty-two color plates-Finite Element Analysis of Antennas and Arrays presents: Time- and frequency-domain formulations and mesh truncation techniques Antenna source modeling and parameter calculation Modeling of complex materials and fine geometrical details Analysis and modeling of narrowband and broadband antennas Analysis and modeling of infinite and finite phased-array antennas Analysis and modeling of antenna and platform interactions Recognizing the strengths of other numerical methods, this book goes beyond the finite element method and covers hybrid techniques that combine the finite element method with the finite difference time-domain method, the method of moments, and the high-frequency asymptotic methods to efficiently deal with a variety of complex antenna problems. Complemented with numerous examples, this cutting-edge resource fully demonstrates the power and capabilities of the finite element analysis and its many practical applications.…

Hardcover. Zustand: Fine. Zustand des Schutzumschlags: Fine. First edition. Fine in fine dustwrapper with a short tear. Advance Review Copy with a publisher's slip laid in.