Leaky-wave long waveguide slot antennas: aperture fields, far field radiation, and mutual coupling

2003 ◽  
Author(s):  
F.L. Whetten ◽  
C.A. Balanis
Keyword(s):  
Mutual Coupling ◽  
Far Field ◽  
Leaky Wave ◽  
Slot Antennas ◽  
Waveguide Slot ◽  
Field Radiation

Novel Compact Mushroom-Type EBG Structure for Electromagnetic Coupling Reduction of Microstrip Antenna array

Frequenz ◽  
2015 ◽  
Vol 69 (3-4) ◽  
Author(s):  
Lizhong Hu ◽  
Guangming Wang ◽  
Jiangang Liang ◽  
Chenxin Zhang
Keyword(s):  
Antenna Arrays ◽  
Microstrip Antenna ◽  
Mutual Coupling ◽  
Electromagnetic Coupling ◽  
Microstrip Antennas ◽  
Far Field ◽  
Electromagnetic Bandgap ◽  
Multiple Input ◽  
Microstrip Antenna Array ◽  
Field Radiation

AbstractA novel compact electromagnetic bandgap (EBG) structure consisting of two turns complementary spiral resonator (CSR) and conventional mushroom EBG (CM-EBG) structure is introduced to suppress the mutual coupling in antenna arrays for multiple-input and multiple-output (MIMO) applications. Eigenmode calculation is used to investigate the proposed CSR-loaded mushroom-type EBG (MT-EBG), which proved to exhibit bandgap property and a miniaturization of 48.9% is realized compared with the CM-EBG. By inserting the proposed EBG structure between two E-plane coupled microstrip antennas, a mutual coupling reduction of 8.13 dB has been achieved numerically and experimentally. Moreover, the EBG-loaded antenna has better far-field radiation patterns compared with the reference antenna. Thus, this novel EBG structure with advantages of compactness and high decoupling efficiency opens an avenue to new types of antennas with super performances.

Mode structure in the far field radiation of a leaky-wave multiple quantum well laser

2012 ◽  
Vol 42 (10) ◽  
pp. 931-933 ◽  
Author(s):  
S M Nekorkin ◽  
B N Zvonkov ◽  
Maria V Karzanova ◽  
Natalia V Dikareva ◽  
V Ya Aleshkin ◽  
...  
Keyword(s):  
Quantum Well ◽  
Multiple Quantum Well ◽  
Multiple Quantum ◽  
Far Field ◽  
Mode Structure ◽  
Leaky Wave ◽  
Quantum Well Laser ◽  
Field Radiation ◽  
Multiple Quantum Well Laser

The shape of things to come — Development and testing of a new marine vibrator source

2019 ◽  
Vol 38 (9) ◽  
pp. 680-690 ◽  
Author(s):  
Benoît Teyssandier ◽  
John J. Sallas
Keyword(s):  
Seismic Source ◽  
Test Facility ◽  
Data Sets ◽  
Far Field ◽  
Ocean Bottom ◽  
Air Gun ◽  
Seismic Image ◽  
Field Radiation ◽  
Technical Issues ◽  
To Come

Ten years ago, CGG launched a project to develop a new concept of marine vibrator (MV) technology. We present our work, concluding with the successful acquisition of a seismic image using an ocean-bottom-node 2D survey. The expectation for MV technology is that it could reduce ocean exposure to seismic source sound, enable new acquisition solutions, and improve seismic data quality. After consideration of our objectives in terms of imaging, productivity, acoustic efficiency, and operational risk, we developed two spectrally complementary prototypes to cover the seismic bandwidth. In practice, an array composed of several MV units is needed for images of comparable quality to those produced from air-gun data sets. Because coupling to the water is invariant, MV signals tend to be repeatable. Since far-field pressure is directly proportional to piston volumetric acceleration, the far-field radiation can be well controlled through accurate piston motion control. These features allow us to shape signals to match precisely a desired spectrum while observing equipment constraints. Over the last few years, an intensive validation process was conducted at our dedicated test facility. The MV units were exposed to 2000 hours of in-sea testing with only minor technical issues.

Radiation from supersonic faulting

1971 ◽  
Vol 61 (4) ◽  
pp. 1009-1012 ◽  
Author(s):  
J. C. Savage
Keyword(s):  
Initial Point ◽  
Step Function ◽  
Fault Model ◽  
Dislocation Segment ◽  
Far Field ◽  
Fault Propagation ◽  
Unit Step ◽  
Propagation Factor ◽  
Double Couple ◽  
Field Radiation

abstract The far-field radiation from a simple fault model is given by the radiation pattern associated with the appropriate strain nucleus (e.g., double couple) multiplied by a fault propagation factor. For a unilateral fault model the propagation factor is F ( c ; t ) = ζ bd [ H ( τ ) − H ( τ − ( L / ζ ) ( 1 − ( ζ / c ) cos ψ )) ] / ( 1 − ( ζ / c ) cos ψ ) where ξ is the velocity of fault propagation, b is the fault slip, d is the fault width, τ = t − r0/c, r0 is the distance of the observer from the initial point of faulting, c is the velocity of the seismic wave, H(τ) is the unit-step function, L is the length of the fault, and ψ the angle between r0 and the direction of fault propagation. This representation is valid for both subsonic and supersonic fault propagation. The latter case is important because Weertman (1969) has recently shown that spontaneous faulting may propagate at supersonic velocities. Because the propagation factor is always positive, the nodal planes for the radiation are the same as for the appropriate strain nucleus. Finally, it is shown by the application of this equation that the radiation from a screw dislocation segment is represented by the double-couple nucleus, not the compensated linear-vector dipole nucleus as recently suggested by Knopoff and Randall (1970).

A Reciprocity Method of Analysis for Gap Waveguide Slot Antennas

IEEE Access ◽  
2021 ◽  
pp. 1-1
Author(s):  
Mohammad D. Motevalli ◽  
Keyvan Forooraghi ◽  
Jalil Rashed Mohassel
Keyword(s):  
Slot Antennas ◽  
Reciprocity Method ◽  
Waveguide Slot

scholarly journals Light-Emitting Metasurfaces: Simultaneous Control of Spontaneous Emission and Far-Field Radiation

Nano Letters ◽  
2018 ◽  
Vol 18 (11) ◽  
pp. 6906-6914 ◽  
Author(s):  
Sheng Liu ◽  
Aleksandr Vaskin ◽  
Sadhvikas Addamane ◽  
Benjamin Leung ◽  
Miao-Chan Tsai ◽  
...  
Keyword(s):  
Spontaneous Emission ◽  
Far Field ◽  
Light Emitting ◽  
Simultaneous Control ◽  
Field Radiation
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