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In this article, a novel automatically designed electromagnetic bandgap (EBG) structure is presented to prohibit the simultaneous switching noise (SSN) propagation of a system in package. The tool employed for the automatic EBG design is the improved genetic algorithm (GA), which has the advantages of rapid convergence and high precision by combining several improvements reasonably. Meanwhile, the equivalent circuit model and the dispersion diagram of the proposed structure are established to interpret the electromagnetic characteristics of the designed power distribution network (PDN). By removing some patches in a specific area determined by the GA, the surface impedance of PDN can be increased to reduce the SSN coupling. The SSN transmission can be suppressed from 0.37 to 20 GHz at a mitigation level of −50 dB. The measured results agree well with the simulated ones.

In this paper, an improved genetic algorithm (GA) for automatically optimizing electromagnetic bandgap (EBG) structure with good power integrity performance is presented. The traditional GA is improved in several ways including Hamming Distance initialization, elite selection and non-repeating crossover, which can generate initial population charactering solution space in detail, increase crossover efficiency, and accelerate convergence. Furthermore, an EBG structure for power distribution network is optimized with the presented GA method to improve the performances of power integrity. The simultaneous switching noise propagation can be prohibited from 0.38 GHz to 20 GHz with a suppression level of -60 dB. Good agreements between the measured results and the simulation ones are observed.

In this paper, a compact electromagnetic bandgap (EBG) structure for mitigating simultaneous switching noise (SSN) in high-speed mixed signal systems is proposed. Only one spiral slot is etched on the square patch, which constitutes the unit cell of the presented EBG pattern. The equivalent circuit model is developed to interpret the mechanism of the proposed power distribution network structure. By etching slot in the square patch of the EBG pattern, a high impedance is provided for prohibiting the SSN propagation. Furthermore, the capacitance is increased correspondingly, which can enlarge the bandwidth of the SSN suppression performance. An ultrawideband SSN suppression property is achieved from 0.35 to 20 GHz under the suppression level of −40 dB. In comparison with the traditional multiturns spiral EBG structure, not only the bandwidth but also the rejection level can be improved significantly with the presented design. Moreover, the SI performance is investigated, and the corresponding improvement measure is presented. Good agreements are observed between the simulation and measured results.

A compact tapered electromagnetic bandgap (EBG) structure by using complementary split-ring resonator (CSRR) is presented. By employing CSRRs, open stubs, and spurline, three transmission zeros are introduced to improve performances of the EBG structure. Chebyshev tapering distribution reduces the ripples within the passband. In construct with the traditional EBG structure, the slope from the stopband to passband transition can be increased from 12.59 to 45.95 dB/GHz with the presented design. An ultrawide fractional bandwidth of 112.91% within the stopband below −20 dB is also obtained. The measurements agree well with the simulation results.

A semi-analytic solution to the Gaussian beam scattering by a conducting spheroidal particle with non-confocal dielectric coating is obtained within the framework of the generalized Lorenz-Mie theory (GLMT). By virtue of a transformation between spheroidal and spherical vector wave functions, a theoretical procedure is developed to deal with the non-confocal boundary conditions. Numerical results of the normalized differential scattering cross section are evaluated for coated spheroidal particles.

A method of calculating the scattered electromagnetic fields of a multilayered infinite cylinder, for arbitrary incidence of a shaped beam, is presented. A complete set of coefficients, which describes the electromagnetic fields within the different regions of a multilayered infinite cylinder, is determined by solving a system of linear equations derived from the boundary conditions. As an example, for a tightly focused Gaussian beam propagating perpendicularly to the cylinder axis of a two-layered and three-layered infinite cylinder, the three-dimensional (3D) nature of the scattering problem, greatly different from the case of an incident plane wave, is described in detail, and numerical results of the normalized differential scattering cross section are evaluated.