Martin Stumpf

Efficient 2-D Integral Equation Approach for the Analysis of Power Bus Structures With Arbitrary Shape

A 2-D contour integral-equation method for the frequency-domain analysis of arbitrarily shaped power bus structures is presented. The numerically efficient approach allows the rapid and accurate computation of the frequency-dependent transfer parameters between an arbitrary number of ports, as required for embedding the power plane structure into network simulation. A formulation is developed for calculating the voltage distribution between the planes, as well as for determining the resulting radiated fields based on the field-equivalence principle. The method is applied for several test boards including a populated board with a surface-mount decoupling-capacitor network. The suggested approach is well confirmed by an analytical solution for the rectangular structure, by measurement and 3-D full-wave simulation results.

The Time-Domain Contour Integral Method—An Approach to the Analysis of Double-Plane Circuits

The time-domain counterpart of the Okoshis contour integral method is formulated with the aid of the reciprocity theorem of the time-convolution type. A numerical procedure for solving the time-domain reciprocity relation is proposed and validated using an analytical solution based on the eigenfunction expansion and the finite-integration technique. For the former, the time-domain counterpart of the classical double-summation formula for a rectangular power-ground structure is found and evaluated.

Generalized Ray Theory for Time-Domain Electromagnetic Fields in Horizontally Layered Media

Generalized-ray theory for time-domain electromagnetic fields in a horizontally layered medium is developed. It can be considered as the time-domain equivalent of the intensively studied Greens function formulation in frequency domain. After introducing appropriate integral transformations and source-type field representations, the solution is written out in terms of generalized ray constituents whose space-time counterparts are constructed with the aid of the Cagniard–DeHoop technique. The formulation lays the foundation to rigorously study time-domain field behavior in numerous practical topologies where a stratified multilayer is involved, such as planar antennas and circuits, but also electromagnetic compatibility (EMC) and propagation problems. Illustrative numerical results are presented.

Pulsed EM Field Radiation, Mutual Coupling, and Reciprocity of Thin Planar Antennas

The reciprocity theorem of the time-convolution type is used to construct a purely time-domain methodology that makes possible to readily evaluate the pulsed electromagnetic field radiation characteristics of arbitrarily shaped thin planar antennas and their time-domain mutual coupling. The developed computational model provides an insightful description of thin planar antennas that reveals the principal aspects of their pulsed-radiation behavior. The derived self-reciprocity (time-derivative) relation provides a useful means for determining planar antennas radiation characteristics from its response on a plane wave in the receiving state. Moreover, it is demonstrated that this relation may find its applications in consistency checks of general-purpose computational tools. The proposed coupling model indicates the huge savings of computational resources with respect to the traditional approaches such as the finite difference time-domain technique. It is shown that all the obtained results agree well with the (full-wave) finite integration technique.

Analysis of Dispersive Power-Ground Structures Using the Time-Domain Contour Integral Method

The incorporation of dispersive behavior of power-ground structures in the time-domain contour integral method is investigated. It is shown that material dispersion can be accounted for with the help of a numerical method for the inverse Laplace transform. The proposed technique is very versatile and allows for the incorporation of the general (causal) dielectric-relaxation model. In this paper, conduction-loss and Debijes dielectric-relaxation models are closely studied. Numerical examples are validated using the feature selective validation analysis.

Pulsed Electromagnetic Field Radiation From a Wide Slot Antenna With a Dielectric Layer

Analytic time-domain expressions are derived for the pulsed electromagnetic field radiated by a wide slot antenna with a dielectric layer in a two-dimensional model configuration. In any finite time window of observation, exact pulse shapes for the propagated, reflected and refracted wave constituents are constructed with the aid of the modified Cagniard method (the Cagniard-DeHoop method). Numerical results are presented for field pulse shapes at the dielectric/free-space interface, the pulse time widths of the excitation being chosen such that the separate arrivals from the two edges of the slot can be distinguished. Applications are found in any system whose operation is based on pulsed electromagnetic field transfer and where digital signals are detected and interpreted in dependence on their pulse shapes.

The Time-Domain Optical Theorem in Antenna Theory

A special form of the time-domain optical theorem related to a general receiving antenna system is rigorously derived. It is shown that the total energies dissipated in the antenna load and in the antenna system itself can be directly related to the electromagnetic energy of the scattered field and its time-domain far-field characteristics. A practical implication of the result in optimizing antenna scattering properties with regard to the maximum energy dissipated in the antenna loading is discussed.

Time-Domain Analysis of Rectangular Power-Ground Structures With Relaxation

The rectangular power-ground structure is thoroughly analyzed in time domain. The time-dependent electric-field distribution within the power-ground structure is expanded in ray-like constituents that propagate via the reflections against circuits periphery. Their relation to the classical eigenfunction expansion is demonstrated. It is shown that the ray-type expansion is always exact in any finite time window of observation and can be readily generalized to account for dissipation and relaxation mechanisms. Obtained results concerning a dispersive dielectric described through finite conductivity and Debije relaxation models are discussed and validated on a number of illustrative examples.

Controlling pulsed EM scattering of receiving antennas: The one-port case

A time-domain compensation theorem concerning EM scattering of a one-port antenna system is derived with the aid of the reciprocity theorem of the time-convolution type. The theorem describes the impact of a change in the antenna load on receiving-antenna scattering properties. Applications of the theorem are found in controlling the pulsed echo of a receiving antenna as well as in related theoretical aspects of receiving-antenna scattering theory.

Closed-form time-domain expressions for the 2D pulsed EM field radiated by an array of slot antennas of finite width

Closed-form time-domain expressions are derived for the pulsed EM field radiated by a planar array of 2D slot antennas of finite width through the use of the Cagniard-DeHoop technique. Each radiating slot is excited by a uniform electric field crossing the aperture and having a prescribed pulse shape. Mutual coupling between the apertures is neglected. With the results, the time-domain beam-steering and beam-shaping properties of the array can be studied. Parameters in this respect are: the collection of pulse shapes and amplitudes of the excitation and the time delays between the excitation of the successive slots. Numerical illustrations are shown.