Design and experimental characterization of a reconfigurable transmitarray with reduced focal distance

2016 ◽  
Vol 8 (3) ◽  
pp. 447-454 ◽  
Author(s):  
Luca Di Palma ◽  
Antonio Clemente ◽  
Laurent Dussopt ◽  
Ronan Sauleau ◽  
Patrick Potier ◽  
...  
Keyword(s):  
Single Source ◽  
Experimental Characterization ◽  
Focal Distance ◽  
Power Combining ◽  
Spatial Power Combining ◽  
Numerical Predictions ◽  
Beam Tilting ◽  
X Band ◽  
Source Case

In this contribution, we study the design and experimental characterization of a reconfigurable transmitarray in X-band with reduced focal distance. To this end, we consider an illumination with four feed horn antennas in two different configurations. The focal distance and the horn configuration in the focal plane have been optimized with an in-house simulation tool. The effects of source placement errors and excitation unbalances are also studied. The numerical results show a reduction of the focal distance by a factor 1.8 if compared with the single-source case, for a reconfigurable 400-element transmitarray designed in X-band. Moreover, generation of multiple beams is considered and demonstrated numerically for spatial power combining applications. The experimental results obtained in radiation are in good agreement with the numerical predictions. This multiple-source transmitarray exhibits similar radiation performances as the single-source one in terms of gain, bandwidth and beam tilting capabilities, but with about half its volume. This technique seems very attractive for a better integration on various platforms such as vehicles, drones, aircrafts, buildings, etc.

scholarly journals A Setup for Microscopic Studies of Ultrasounds Effects on Microliters Scale Samples: Analytical, Numerical and Experimental Characterization

Pharmaceutics ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 847
Author(s):  
Florian N. Gailliègue ◽  
Mindaugas Tamošiūnas ◽  
Franck M. André ◽  
Lluis M. Mir
Keyword(s):  
Culture Medium ◽  
Small Volume ◽  
Acoustic Pressure ◽  
Experimental Characterization ◽  
Focal Distance ◽  
Microscopic Studies ◽  
Cell Membrane Permeabilization ◽  
Ultrasonic Parameters ◽  
Rigid Walls

Sonoporation is the process of cell membrane permeabilization, due to exposure to ultrasounds. There is a lack of consensus concerning the mechanisms of sonoporation: Understanding the mechanisms of sonoporation refines the choice of the ultrasonic parameters to be applied on the cells. Cells’ classical exposure systems to ultrasounds have several drawbacks, like the immersion of the cells in large volumes of liquid, the nonhomogeneous acoustic pressure in the large sample, and thus, the necessity for magnetic stirring to somehow homogenize the exposure of the cells. This article reports the development and characterization of a novel system allowing the exposure to ultrasounds of very small volumes and their observation under the microscope. The observation under a microscope imposes the exposure of cells and Giant Unilamellar Vesicles under an oblique incidence, as well as the very unusual presence of rigid walls limiting the sonicated volume. The advantages of this new setup are not only the use of a very small volume of cells culture medium/microbubbles (MB), but the presence of flat walls near the sonicated region that results in a more homogeneous ultrasonic pressure field, and thus, the control of the focal distance and the real exposure time. The setup presented here comprises the ability to survey the geometrical and dynamical aspects of the exposure of cells and MB to ultrasounds, if an ultrafast camera is used. Indeed, the setup thus fulfills all the requirements to apply ultrasounds conveniently, for accurate mechanistic experiments under an inverted fluorescence microscope, and it could have interesting applications in photoacoustic research.

X-band power transmitting module based on waveguide spatial power combining

2009 ◽  
Author(s):  
Zenon R. Szczepaniak ◽  
Andrzej Arvaniti ◽  
Jaroslaw Popkowski ◽  
Emanuela Orzel-Tatarczuk
Keyword(s):  
Power Combining ◽  
Spatial Power Combining ◽  
Band Power ◽  
X Band

Experimental characterization of electromagnetic cloaking structures with bistatic measurements at X-band

2012 ◽  
Author(s):  
Pekka Alitalo ◽  
Ali E. Culhaoglu ◽  
Andrey V. Osipov ◽  
Stefan Thurner ◽  
Erich Kemptner ◽  
...  
Keyword(s):  
Experimental Characterization ◽  
X Band

scholarly journals Experimental Characterization of 2 × 2 Electronically Reconfigurable 1 Bit Unit Cells for a Beamforming Transmitarray at X Band

2021 ◽  
Vol 21 (2) ◽  
pp. 153-160
Author(s):  
Biswarup Rana ◽  
In-Gon Lee ◽  
Ic-Pyo Hong
Keyword(s):  
Phase Shifter ◽  
Unit Cell ◽  
Experimental Characterization ◽  
Waveguide Transition ◽  
Transmitted Waves ◽  
X Band ◽  
Unit Cells ◽  
New Type ◽  
Good Agreement

This paper proposes a reconfigurable unit cell for a transmitarray operating at the X band. The unit cell consists of an active patch, a passive patch, and a phase shifter. The active patch has two PIN diodes that change the phase of 180° of the transmitted waves. The passive and active patches both have circular slots to enhance the bandwidth of the transmitted wave. We also propose a new type of experimental characterization technique to measure the performance of the unit cells at the X band without fabricating the entire transmitarray. Instead of a 1 unit cell as described in the literature, we propose 2 × 2 unit cells to measure the performance of unit cells using the X band waveguide. The waveguide consists of a WR-90 section and a rectangular to square waveguide transition section that can be fit to our proposed structure. A good agreement between simulated and measured results was found.

Experimental characterization of a broadband dual-polarized microstrip antenna for X-band SAR applications

2007 ◽  
Vol 49 (3) ◽  
pp. 649-652 ◽  
Author(s):  
Wei Wang ◽  
Xian-Ling Liang ◽  
Yu-Mei Zhang ◽  
Shun-Shi Zhong ◽  
Yan Guo
Keyword(s):  
Microstrip Antenna ◽  
Experimental Characterization ◽  
X Band ◽  
Dual Polarized
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