13,139 research outputs found
Generalized Debye Sources Based EFIE Solver on Subdivision Surfaces
The electric field integral equation is a well known workhorse for obtaining
fields scattered by a perfect electric conducting (PEC) object. As a result,
the nuances and challenges of solving this equation have been examined for a
while. Two recent papers motivate the effort presented in this paper. Unlike
traditional work that uses equivalent currents defined on surfaces, recent
research proposes a technique that results in well conditioned systems by
employing generalized Debye sources (GDS) as unknowns. In a complementary
effort, some of us developed a method that exploits the same representation for
both the geometry (subdivision surface representations) and functions defined
on the geometry, also known as isogeometric analysis (IGA). The challenge in
generalizing GDS method to a discretized geometry is the complexity of the
intermediate operators. However, thanks to our earlier work on subdivision
surfaces, the additional smoothness of geometric representation permits
discretizing these intermediate operations. In this paper, we employ both ideas
to present a well conditioned GDS-EFIE. Here, the intermediate surface
Laplacian is well discretized by using subdivision basis. Likewise, using
subdivision basis to represent the sources, results in an efficient and
accurate IGA framework. Numerous results are presented to demonstrate the
efficacy of the approach
Unveiling Magnetic Dipole Radiation in Phase-Reversal Leaky-Wave Antennas
The radiation principle of travelling-wave type phase-reversal antennas is
explained in details, unveiling the presence of magnetic-dipole radiation in
addition to well-known electric dipole radiation. It is point out that such
magnetic dipole radiation is specific to the case of traveling-wave
phase-reversal antennas whereas only electric-dipole radiation exists in
resonant-type phase-reversal antennas. It is shown that a phase-reversal
travelling-wave antenna alternately operates as an array of magnetic dipoles
and an array of electric-dipoles during a time-harmonic period. This radiation
mechanism is confirmed through both full-wave and experimental results.Comment: 4 pages, 3 figure
Magneto-Electric Dipole Antenna Arrays
A planar magneto-electric (ME) dipole antenna array is proposed and
demonstrated by both full-wave analysis and experiments. The proposed structure
leverages the infinite wavelength propagation characteristic of composite
right/left-handed (CRLH) transmission lines to form high-gain magnetic
radiators combined with radial conventional electric radiators, where the
overall structure is excited by a single differential feed. The traveling-wave
type nature of the proposed ME-dipole antenna enables the formation of
directive arrays with high-gain characteristics and scanning capability. Peak
gains of 10.84 dB and 5.73 dB are demonstrated for the electric dipole and
magnetic-dipole radiation components, respectively.Comment: 9 pages, 17 figure
Microwave millisecond spike emission and its associated phenomena during the impulsive phase of large flares
A tentative model is proposed to account for some features of the microwave millisecond spike emission and its links with the physical processes of associated phenomena during the impulsive phase of large flares by comparing the optical, radio, and X-ray observations on May 16, 1981 to those on October 12, 1981
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