W. Y. Yin

Comparative characteristics of on-chip single- and double-level square inductors

Detailed experimental investigations reported in this paper have determined the inductances, Q factors, and resonance frequencies of on-chip square, single-level (SL) and double-level (DL) inductors on silicon substrates, using the equivalent circuit model and the measured S parameters. Parametric studies show the effects of both strip length and inner empty area on the coupling capacitance and resonance frequency. Some scalable formulas are derived for extrapolating inductance and resonance frequency of other inductors. In the DL chips, very strong self-resonance can take place with lower resonance frequency, and the Q factor will be degraded rapidly.

Electromagnetic Fields of a Thin Circula Loop Antenna above a (Un)Grounded Multi-Layered Chiral Slabs: The Non-Uniform Current Excitation

The technique of dyadic Green’s function (DGF) expressed in terms of the normalised cylindrical vector wave functions is adopted in this study for examining the electromagnetic fields excited by one thin circular loop antenna above a (un)grounded multi-layered chiral slabs. The current carried on such a circular loop antenna is expressed in a generalized Fourier series so as to incorporate practical situations. Thereby, exact representations of the radiated fields in both near and far zones are obtained in closed form, in a superposition of the rightand left-handed circularly polarized waves. Furthermore, numerical results are presented to show the radiation characteristics of the loop antenna in different layered chiral slab structures. The contributions of the loweras well as higher-order current excitations to the far-zone field are examined in detail.

Electrical Characteristics and Behavioral Model of Spiral Inductors On Gaas Substrate

Extensive experimental results for various square spiral inductors on GaAs substrate are presented in this paper. Through detailed studies of the inductances extracted from the de-embedded on-chip measured S-parameters, the relationships between the electrical characteristics and the geometrical parameters of the spiral inductors are revealed. Based on the curve fitting technique, a behavioral model for spiral inductors is obtained and presented. Thus, the inductances of spiral inductors with an acceptable accuracy up to their first resonance frequencies are obtained.

The Near- and Far-Zone Fields of Periodic Spherical Arrays of Dipole Antennas on Spherical Chiral Substrates

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DISTORTION OF PULSE WAVES PROPAGATING IN SOME FERRITE MICROSTRIP TRANSMISSION LINES

The distortion of pulse waves propagating in some shielded composite ferrite microstrip transmission lines (FMTLs) is studied in this paper. The mathematical treatment is based on the Galerkins method in the spectral domain and the fast Fourier transformation (FFT). The hybrid effects of the biasing magnetic dc field intensity and its orientation on the pulse wave distortion are examined and compared. It is shown that the pulse distortion can be effectively reduced by changing the biasing field intensity or orientation.

Electromagnetic fields of a thin circula loop antenna above a (un)grounded multi-layered chiral slabs : The non-uniform current excitation : Abstract

The technique of dyadic Greens function (DGF) expressed in terms of the normalised cylindrical vector wave functions is adopted in this study for examining the electromagnetic fields excited by one thin circular loop antenna above a (un)grounded multi-layered chiral slabs. The current carried on such a circular loop antenna is expressed in a generalized Fourier series so as to incorporate practical situations. Thereby, exact representations of the radiated fields in both near and far zones are obtained in closed form, in a superposition of the right-and left-handed circularly polarized waves. Furthermore, numerical results are presented to show the radiation characteristics of the loop antenna in different layered chiral slab structures. The contributions of the lower- as well as higher-order current excitations to the far-zone field are examined in detail.

THE NEAR- AND FAR-ZONE FIELDS OF PERIODIC SPHERICAL ARRAYS OF DIPOLE ANTENNAS ON SPHERICAL CHIRAL SUBSTRATES

This paper presents an analytic formulation of the near- and far-field distributions due to periodic spherical arrays of dipole antennas on two spherical biisotropic substrates, i.e., on the chiral sphere and on a perfectly conducting sphere coated with one-layer chiral medium, respectively. For an arbitrary orientation of the dipole antenna array, the dyadic Greens functions in the form of an eigenfunction expansion in terms of the normalized spherical vector wave functions are directly employed. Thereby, exact representations of the radiated fields in both near and far zones are obtained in closed form. They are all in a superposition of right- and left-handed circularly polarized waves, and are also applicable for the cases of spherical arrays of dipole antennas on spherical isotropic substrates. Furthermore, the constitutive parameter effects of the chiral medium on the three-dimensional patterns of the far-zone field and its polarized feature are demonstrated numerically.

FDTD and PSTD simulations for double negative (DNG) materials applications

As a full wave simulation method, the finite-difference time-domain (FDTD) method is capable of capturing the transient characteristics of wave propagation. This method has been successfully used in modeling the interactions of electromagnetic waves with double negative (DNG) materials. Another method, the pesudospectral time-domain (PSTD) method, is superior to FDTD in its linear dispersion relation. Another advantage of PSTD is that all field components are now located at a same position in the unit cell. Therefore, it is more natural to handle the boundary condition on interfaces between different materials. In this paper, FDTD and PSTD are used to simulate the transient evolution of wave propagation in structures with DNG materials. Numerical results are given to provide clear descriptions of the novel wave behaviors.

The Mueller Matrix of a Two-Layer Eccentrically Bianisotropic Cylinder Linear Array With Double Helical Conductances of the Surfaces: Clarification of the Magnetic Symmetry Groups - Abstract

Unique effects of the double helical conductances of the surfaces (HCS) on the Mueller matrix (Mm) of a two-layer eccentrically bianisotropic cylinder linear array are investigated in this paper. The mathematical treatment is conducted based on the boundary-value approach combined with the technique of generalized separation variables. Both the TMz- and TEz-polarization of the obliquely incident waves are taken into account in the analysis. To gain insight into some physical mechanisms, numerical examples are presented to show the influences of the variations of the twist angles on the behavior of Mm of a linear array of four bianisotropic cylinders. Correspondingly, various magnetic symmetry groups (such as D∞(C∞), C∞v(C∞), D∞h(D∞), C∞h(C∞)) and some generalized symmetry and anti-symmetry relations, which govern all the elements of Mm or the scattering cross section under special chiral operations, are demonstrated. The present studies can be exploited to identify the constitutive characteristics of some bianisotropic media and to provide better understanding of the electromagnetic wave interaction with bianisotropic cylindrical objects with complex boundaries.