Kazuhiko Atsuki

Analysis of Microstrip-Like Transmission Lines by Nonuniform Discretization of Integral Equations

The nonuniform discretization of the integral equation on the tangential electromagnetic (EM) field on the boundary surface is proposed as a numerically efficient method to analyze the microstrip-like transmission lines. The calculated results of the propagation constant of the microstrip line based on this method are compared with other published analytical results. Various types of planar striplines are treated by the same formulas. The dominant and higher order modes of shielded microstrip line are discussed and compared with the longitudinal-section electric (LSE) and linear synchronous motor (LSM) modes of a two-medium waveguide.

Analysis Method for Generalized Suspended Striplines

This, paper describes an effective analysis method suited to generalized suspended striplines, that is, planar transmission lines having multiple conductor sheets on multiple substrates, and multiple supporting grooves or pedestals. Two example striplines structures are analyzed based on this method. Some experimental results are also shown.

Transmission line aspects of the design of broad-band electrooptic traveling-wave modulators

This paper proposes a two-layer traveling-wave type electrooptic modulator structure to maximize modulation bandwidth from transmission line aspects. This structure can be designed to satisfy the velocity matching and impedance matching condition simultaneously. A design method for this structure is discussed.

Effects of Side-Wall Grooves on Transmission Characteristics of Suspended Striplines

The use of suspended striplines is becoming an important transmission-line technique at millimeter wavelengths because of low attenuation, weak dispersion, and various merits in manufacturing processes. This paper estimates the effects of side-wall grooves of these lines on transmission characteristics within the TEM wave approximation.

Characterization of microstrip lines near a substrate edge and design formulas of edge-compensated microstrip lines (MMICs)

The proximity effects of microstrip lines near a substrates edge present a problem for effectively designing high-packing-density MMICs (monolithic microwave integrated circuits). Proximity effects of this type are analyzed using the rectangular boundary division method. It is assumed that the cross-sectional dimensions of transmission lines in the MMICs are small compared with the wavelengths to allow the use of the quasi-TEM-wave approximation. Then, the concept of edge-compensated microstrip lines to keep the characteristic impedance constant near a substrate edge is introduced to circumvent the proximity effects and to expand the interconnection flexibility of microstrip lines on MMIC substrates. The practical design parameters of edge-compensated 50- Omega microstrip lines are given in the form of numerical data and simple polynomials for CASD (computer-aided design) work with a curve-fitting procedure. Results of capacitance measurements are compared with this theory with errors of about 1% resulting. >

General analytical solutions of static Green's functions for shielded and open arbitrarily multilayered media

In this paper, we present for the first time general analytical solutions of the static Greens functions for shielded and open arbitrarily multilayered media. The analytical formulas for the static Greens functions, which are expressed in the form of the Fourier series or the Fourier integrals, have simple form and are applicable to arbitrary number of the dielectric layers. The derivation of the formulas is primarily based on a technique by which a recurrence relation between L layers and L+1 layers is developed. Greens functions for a three-layered dielectric structure are given as an example of the general formulas. These general analytical solutions will provide a new and efficient tool to the analysis of the multilayered medium structures.

Application of MIC Formulas to a Class of Integrated-Optics Modulator Analyses: A Simple Transformation (Short Papers)

Modulation electric fields in a class of planar, lumped-parameter circuit or traveling-wave-type electrooptic modulators in integrated optics are analyzed by applying a simple transformation of variables to presently available formulas on microwave integrated circuits (MICs). Example calculations are shown.

Modal dispersion control and distortion suppression of picosecond pulses in suspended coplanar waveguides

The propagation and dispersion characteristics of picosecond electrical pulses in a suspended coplanar waveguide (SCPW) are investigated, and it is shown that the SCPW is a very promising transmission structure for ultrashort pulses. Numerical results for the modal dispersion of the SCPW are presented and compared to those of the conventional CPW, and a field-coupling theory is used to explain the evolution in the dispersion behavior. An evaluation based on the numerical analysis shows that a SCPW with properly controlled dispersion can exhibit a five times improvement in pulse transmission capability compared to the conventional CPW. Both computer simulations and experimental measurements show a substantial suppression in pulse distortion as well, compared to conventional CPWs. >

Partial-boundary element method for analysis of striplines with arbitrary cross-sectional dielectric in multi-layered media

A new method of analysis called the partial-boundary element method (p-BEM) is proposed for the analysis of striplines with arbitrary cross-sectional dielectric in multi-layered media. By using a Greens function that satisfies the boundary conditions of a relevant structure with multi-layered media and introducing a concept of the equivalent charge density, the p-BEM formulates a potential integral and boundary integral equations only on partial-boundaries such as the surface of the arbitrary cross-sectional dielectric. The number of the equations needed to be formulated is much less than in the conventional BEM. Numerical results of analysis are presented for two kinds of striplines: 1) with a rectangular dielectric ridge and 2) with an embedded rectangular dielectric in three-layered media. >

Application of Microstrip Analysis to the Design of a Broad-Band Electrooptical Modulator (Short Papers)

This short paper describes a proposed structure of a broad-band electrooptical modulator and an application of existing microstrip analysis programs to determine dimensions of the structure for a broad-band property. Results of numerical computations indicate that it is possible to obtain a broad-band modulator by using LiNbO/sub 3/ or LiTaO/sub 3/.