Characterization of an OAM antenna using a flat phase plate in the millimeter frequency Band

2014 ◽  
Author(s):  
R. Niemiec ◽  
C. Brousseau ◽  
K. Mahdjoubi ◽  
O. Emile ◽  
A. Menard
Keyword(s):  
Frequency Band ◽  
Phase Plate

Additive technology applied to the realization of K-band microwave terminations: reproducibility improvement

2018 ◽  
Vol 10 (1) ◽  
pp. 3-8
Author(s):  
Azar Maalouf ◽  
Ronan Gingat ◽  
Vincent Laur
Keyword(s):  
3D Printing ◽  
Frequency Band ◽  
Rectangular Waveguide ◽  
Three Dimensional ◽  
Low Density ◽  
Support Material ◽  
Additive Technology ◽  
3D Printed ◽  
K Band

This study examines K-band rectangular waveguide terminations with three-dimensional (3D)-printed loads, and proposes an Asymmetrical Tapered Wedge topology. This geometry shows a good tradeoff between microwave performance and 3D-printing issues (printing directions and support material requirements), thus improving noticeably the reproducibility of the devices. The effect of the density of the 3D-printed load on the reflection parameter of the termination was investigated. Even for a low density, reflection level remained below −27.5 dB between 18 and 26.5 GHz. Reproducibility was demonstrated by the characterization of six loads that were 3D printed under the same conditions. Measurements demonstrate that a maximum reflection parameter level of −33.5 dB can be ensured over the whole frequency band without any post-machining of the 3D-printed devices.

Electromagnetic Characterization of Hemp Concrete in the 2.4 GHz WiFi Frequency Band

2018 ◽  
Author(s):  
Mehdi Ferhat ◽  
Fares Bennai ◽  
Badreddine Ratni ◽  
Eric Vourch ◽  
Kamilia Abahri ◽  
...  
Keyword(s):  
Frequency Band

scholarly journals Characterization of the Vortex Beam by Fermat’s Spiral

Photonics ◽  
2020 ◽  
Vol 7 (4) ◽  
pp. 102
Author(s):  
Ewa Frączek ◽  
Agnieszka Popiołek-Masajada ◽  
Sławomir Szczepaniak
Keyword(s):  
Phase Distribution ◽  
Phase Plate ◽  
Vortex Beam ◽  
Scanning Microscope ◽  
Object Beam ◽  
Fitting Method ◽  
Numerical Fitting ◽  
Helical Beam ◽  
Spiral Phase

In this paper, we characterize the helical beam structure through an analysis of the spiral character of the phase distribution inside a light beam. In particular, we show that a line connected with the 2π phase jump in the Laguerre–Gauss beam can be described by a Fermat’s spiral. We propose a numerical fitting method to determine the parameters of a spiral equation for the phase distribution of the helical beam. Next, we extend the procedure to a vortex beam created by the spiral phase plate and apply it to experimental phase maps, which allows us to recover the phase shift introduced into the object beam in the optical vortex scanning microscope.

scholarly journals Fast Frequency Sweep Technique Based on Segmentation for the Acceleration of the Electromagnetic Analysis of Microwave Devices

2019 ◽  
Vol 9 (6) ◽  
pp. 1118
Author(s):  
Juan Martinez ◽  
Angel Belenguer ◽  
Héctor Esteban
Keyword(s):  
Frequency Band ◽  
Rectangular Waveguide ◽  
Building Blocks ◽  
Frequency Sweep ◽  
Discrete Frequency ◽  
Natural Cubic Splines ◽  
Communication Devices ◽  
Waveguide Filter ◽  
Electromagnetic Solver

The characterization of communication devices in a certain frequency band can be accelerated if a fast frequency sweep technique is used instead of a discrete frequency sweep. Existing fast frequency sweep techniques are either complex or specific for a certain electromagnetic solver. In this work, a new fast frequency sweep method is proposed that consists in segmenting the device under analysis into simple building blocks. Each building block is characterized with a generalized (multimode) circuital matrix whose elements present a simple and flat frequency response that is interpolated using natural cubic splines with very few points. In this way, the response of each block along the whole frequency band is obtained efficiently and accurately with as many frequency points as desired. Then, the circuital matrices of all the blocks are cascaded and the circuital matrix of the whole device in obtained. The new fast frequency sweep was successfully applied to the analysis of different types of devices (all metallic rectangular waveguide filter, dielectric loaded rectangular waveguide filter, and substrate integrated waveguide filter). The computational times were reduced to 15% or 19%, depending on the device, when compared with a discrete frequency sweep using the same electromagnetic solver.

scholarly journals Design and optical characterization of a large continuous phase plate for Laser Integration Line and laser Megajoule facilities

2003 ◽  
Vol 42 (13) ◽  
pp. 2377 ◽  
Author(s):  
Jérôme Néauport ◽  
Xavier Ribeyre ◽  
Jérôme Daurios ◽  
Denis Valla ◽  
Martine Lavergne ◽  
...  
Keyword(s):  
Optical Characterization ◽  
Continuous Phase ◽  
Phase Plate

scholarly journals Polarization Characterization of LEDs by Stokes Parameters Measurements

2022 ◽  
Vol 2149 (1) ◽  
pp. 012009
Author(s):  
T Saito ◽  
T Sutani ◽  
K Kiyono ◽  
T Oikawa
Keyword(s):  
Vertical Plane ◽  
Horizontal Direction ◽  
Stokes Parameters ◽  
Degree Of Polarization ◽  
Observation Angle ◽  
Phase Plate ◽  
Zero Values ◽  
Possible Cause ◽  
Partial Polarization

Abstract Stokes parameters have been measured by using a polarimeter consisting of a rotating phase plate before a fixed polarizer for bullet-shaped red, green and blue LEDs at 3 different directions of 0°, 45° and 90° from the principal axis. The degree of polarization is minimum at the observation angle 0° (observed head-on) for all colors as expected but has non-zero values (1-9%). As for the possible cause for the partial polarization, it is likely to be brought by striae inside the transparent epoxy resin that can be easily visible. Data at observation angle 90° have features common for all colors; the degree of polarization is highest, the long axis azimuth of the polarization ellipse is nearly in the horizontal direction, and the ellipticity is small. These features can be explained as follows. At observation angle 90°, only small fraction of the beam emitted nearly horizontally is detected possibly through multireflection (the plane of incidence is in the vertical plane) inside the top- and bottom-surfaces (in the horizontal direction) of the chip substrate. Since the reflectance for s-polarization (horizontal component) is higher than that for p-polarization, the emerging beam becomes horizontally polarized. The hypotheses that geometrical asymmetry generates polarization is experimentally supported.

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