Contribution to the understanding of pattern coverage of an open-circuited microstrip wraparound antenna acting at half-wavelength resonance

1983 ◽  
Vol 19 (14) ◽  
pp. 505
Author(s):  
G. Dubost
Keyword(s):  
Half Wavelength

scholarly journals Thermos Array: Two-Dimensional Sparse Array with Reduced Mutual Coupling

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Lei Sun ◽  
Minglei Yang ◽  
Baixiao Chen
Keyword(s):  
Closed Form ◽  
Degrees Of Freedom ◽  
Mutual Coupling ◽  
Doa Estimation ◽  
Two Dimensional ◽  
Spatial Smoothing ◽  
Planar Arrays ◽  
Half Wavelength ◽  
Planar Array ◽  
Small Spacing

Sparse planar arrays, such as the billboard array, the open box array, and the two-dimensional nested array, have drawn lots of interest owing to their ability of two-dimensional angle estimation. Unfortunately, these arrays often suffer from mutual-coupling problems due to the large number of sensor pairs with small spacing d (usually equal to a half wavelength), which will degrade the performance of direction of arrival (DOA) estimation. Recently, the two-dimensional half-open box array and the hourglass array are proposed to reduce the mutual coupling. But both of them still have many sensor pairs with small spacing d, which implies that the reduction of mutual coupling is still limited. In this paper, we propose a new sparse planar array which has fewer number of sensor pairs with small spacing d. It is named as the thermos array because its shape seems like a thermos. Although the resulting difference coarray (DCA) of the thermos array is not hole-free, a large filled rectangular part in the DCA can be facilitated to perform spatial-smoothing-based DOA estimation. Moreover, it enjoys closed-form expressions for the sensor locations and the number of available degrees of freedom. Simulations show that the thermos array can achieve better DOA estimation performance than the hourglass array in the presence of mutual coupling, which indicates that our thermos array is more robust to the mutual-coupling array.

Hydrodynamic coefficients of a floater near a partially reflecting seawall in the presence of an array of caisson blocks

2021 ◽  
pp. 1-23
Author(s):  
K G Vijay ◽  
Santanu Koley ◽  
Kshma Trivedi ◽  
Chandra Shekhar Nishad
Keyword(s):  
Wave Scattering ◽  
Structural Parameters ◽  
Wave Force ◽  
Vertical Force ◽  
Hydrodynamic Coefficients ◽  
Floating Structure ◽  
Surface Gravity Wave ◽  
Damping Coefficients ◽  
Half Wavelength ◽  
Scattering And Radiation

Abstract In the present study, surface gravity wave scattering and radiation by a freely floating rectangular buoy placed near a partially reflecting seawall and in the presence of an array of caisson blocks are analyzed. Various hydrodynamic parameters related to the wave scattering and radiation, such as the added mass and radiation damping coefficients, correspond to sway, heave and roll motions of the floating buoy, horizontal force, vertical force and moment acting on the floating structure, and horizontal wave force acting on the partially reflecting seawall are studied for a variety of wave and structural parameters. The study reveals that the resonating pattern in various hydrodynamic coefficients occurs for moderate values of the wavenumber. Further, when the distance between the floater and the sidewall is an integral time of half wavelength, the resonating behavior in the sway, heave and roll added masses, and associated damping coefficients appears, and the aforementioned hydrodynamic coefficients change rapidly around this zone. These resonance phenomena can be diminished significantly with appropriate positioning of the floater with respect to the sidewall and in the presence of partially reflecting seawall.

Sub-half-wavelength atom localization via two standing waves

2017 ◽  
Vol 95 (3) ◽  
pp. 305-309 ◽  
Author(s):  
Haifeng Xu
Keyword(s):  
Quantum Interference ◽  
High Efficiency ◽  
Quantum Information Processing ◽  
One Dimensional ◽  
Half Wavelength ◽  
Potential Applications ◽  
Phase Gate ◽  
Quantum Error ◽  
Excited State Population ◽  
Atom Localization

We present a simple scheme of high-efficiency one-dimensional (1D) atom localization via manipulation of excited state population in a four-level inverted-Y atomic system. Because of the joint quantum interference induced by the two standing-wave fields, the 100% detecting probability of the atom in the subwavelength domain appears when the corresponding conditions are satisfied. The proposed scheme may open a promising way to achieve high-precision and high-efficiency 1D atom localization, which provides some potential applications to spatially selective single-qubit phase gate, entangling gates, and quantum error correction for quantum information processing.

Half-wavelength power transmission lines

IEEE Spectrum ◽  
1965 ◽  
Vol 2 (1) ◽  
pp. 87-92 ◽  
Author(s):  
F. J. Hubert ◽  
M. R. Gent
Keyword(s):  
Transmission Lines ◽  
Power Transmission ◽  
Power Transmission Lines ◽  
Half Wavelength
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