An approach to determine solution properties in micro pipes by near-field microwave microscopy

2021 ◽  
Author(s):  
Yahui Wang ◽  
Ziqian Wei ◽  
Yujie Chen ◽  
Quanxin Zhou ◽  
Yubin Gong ◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
Simulation Model ◽  
Near Field ◽  
Electromagnetic Properties ◽  
Electromagnetic Simulation ◽  
Solution Properties ◽  
Microwave Microscopy ◽  
Photinia X Fraseri ◽  
Saline Solutions ◽  
Non Destructive

Abstract In this article, we propose a quantitative, non-destructive and noninvasive approach to obtain electromagnetic properties of liquid specimens utilizing a home-designed near-field microwave microscopy. The responses of aqueous solutions can be acquired with varying concentrations, types (CaCl2, MgCl2, KCl and NaCl) and tip-sample distances. An electromagnetic simulation model also successfully predicts the behaviors of saline samples. For a certain type of solutions with varying concentrations, the results are concaves with different bottoms, and the symmetric graphs of concave extractions can clearly identify different specimens. Moreover, we obtain electromagnetic images of capillaries with various saline solutions, as well as a photinia x fraseri Dress leaf.

Vortex Beam Optimization Design of Concentric Uniform Circular Array Antenna with Improved Array Factor

2021 ◽  
Vol 36 (7) ◽  
pp. 830-837
Author(s):  
Qiang Feng ◽  
Yifeng Lin ◽  
Yushan Zheng ◽  
Long Li
Keyword(s):  
Simulation Model ◽  
Optimization Design ◽  
Near Field ◽  
Electromagnetic Simulation ◽  
Vortex Beam ◽  
Circular Array ◽  
Power Conservation ◽  
Beam Radiation ◽  
Low Sidelobe ◽  
Measurement Results

In this paper, an improved array factor of the concentric uniform circular array (CUCA) antenna is proposed for the orbital angular momentum (OAM) vortex beam optimization design. From the perspective of the radiation pattern’s power conservation principle, a correction factor is introduced to the conventional array factor of CUCA. Then, based on the improved array factor, by adjusting the rings’ radii parameters of the CUCA, we optimize the vortex beam’s sidelobe level through the generic algorithm (GA). Two different CUCA antenna model are calculated as examples to further illustrate the effectiveness of the improved array factor. Subsequently, an electromagnetic simulation model of two rings CUCA antenna is built at C band for generating low sidelobe vortex beam carrying OAM mode. The electromagnetic simulation model of the designed CUCA antenna is also fabricated and measured. The corresponding antenna far-field vortex beam radiation pattern and near-field vortex wave electric field distributions are measured. The simulation results and the measurement results are in good agreement. The proposed designs of antenna and OAM vortex beam regulation are expected to be used for 5G and 6G communications applications

scholarly journals Visualization of microwave near-field distribution in sodium chloride and glucose aqueous solutions by a thermo-elastic optical indicator microscope

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Zhirayr Baghdasaryan ◽  
Arsen Babajanyan ◽  
Levon Odabashyan ◽  
Jung-Ha Lee ◽  
Barry Friedman ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Aqueous Solutions ◽  
Field Distribution ◽  
Near Field ◽  
Absorption Properties ◽  
Novel Approach ◽  
Concentration Changes ◽  
Biological Liquids ◽  
Optical Indicator ◽  
Distribution Intensity

AbstractIn this study, a new optical method is presented to determine the concentrations of NaCl and glucose aqueous solutions by using a thermo-elastic optical indicator microscope. By measuring the microwave near-field distribution intensity, concentration changes of NaCl and glucose aqueous solutions were detected in the 0–100 mg/ml range, when exposed to microwave irradiation at 12 GHz frequency. Microwave near-field distribution intensity decreased as the NaCl or glucose concentration increased due to the changes of the absorption properties of aqueous solution. This method provides a novel approach for monitoring NaCl and glucose in biological liquids by using a CCD sensor capable of visualizing NaCl and glucose concentrations without scanning.

scholarly journals Roll-to-Roll In-Line Implementation of Microwave Free-Space Non-Destructive Evaluation of Conductive Composite Thin Layer Materials

2021 ◽  
Vol 11 (1) ◽  
pp. 378
Author(s):  
Grigorios Koutsoukis ◽  
Ivan Alic ◽  
Antonios Vavouliotis ◽  
Ferry Kienberger ◽  
Kamel Haddadi
Keyword(s):  
Thin Film ◽  
Composite Materials ◽  
Free Space ◽  
Near Field ◽  
Line Production ◽  
Roll To Roll ◽  
Corrugated Horn ◽  
Evaluation Module ◽  
Microwave Nondestructive Testing ◽  
Non Destructive

A free-space microwave nondestructive testing and evaluation module is developed for the low-power, non-ionizing, contactless, and real-time characterization of doped composite thin-film materials in an industrial context. The instrumentation proposed is built up with a handled vector network analyzer interfaced with corrugated horn antennas to measure the near-field complex reflection S11 of planar prepreg composite materials in a roll-to-roll in-line production line. Dedicated modeling and calibrations routines are developed to extract the microwave conductivity from the measured microwave signal. Practical extraction of the radiofrequency (RF) conductivity of thin film prepreg composite materials doped with nano-powders is exemplary shown at the test frequency of 10 GHz.

scholarly journals Improvement of spatial resolution by tilt correction in near-field scanning microwave microscopy

AIP Advances ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 035114
Author(s):  
Xianfeng Zhang ◽  
Zhe Wu ◽  
Quansong Lan ◽  
Zhiliao Du ◽  
Quanxin Zhou ◽  
...  
Keyword(s):  
Spatial Resolution ◽  
Near Field ◽  
Tilt Correction ◽  
Microwave Microscopy ◽  
Scanning Microwave Microscopy ◽  
Near Field Scanning

Microwave Absorbing Ferrite Thin Films for Microwave Heating of Microstructured Reactors

2009 ◽  
Vol 1222 ◽  
Author(s):  
Pengzhao Gao ◽  
Evgeny V. Rebrov ◽  
Jaap C. Schouten ◽  
Richard Kleismit ◽  
John Cetnar ◽  
...  
Keyword(s):  
Thin Films ◽  
Grain Size ◽  
Microwave Heating ◽  
Near Field ◽  
Coplanar Waveguide ◽  
Sol Gel ◽  
Microwave Cavity ◽  
Silicon Substrates ◽  
Microwave Microscopy ◽  
Zn Ferrite

AbstractNanocrystalline Ni0.5Zn0.5Fe2O4 thin films have been synthesized with various grain sizes by sol–gel method on polycrystalline silicon substrates. The morphology and microwave absorption properties of the films calcined in the 673–1073 K range were studied by using XRD, AFM, near–field evanescent microwave microscopy, coplanar waveguide and direct microwave heating measurements. All films were uniform without microcracks. The increase of the calcination temperature from 873 to 1073 K and time from 1 to 3h resulted in an increase of the grain size from 12 to 27 nm. The complex permittivity of the Ni-Zn ferrite films was measured in the frequency range of 2–15 GHz. The heating behavior was studied in a multimode microwave cavity at 2.4 GHz. The highest microwave heating rate in the temperature range of 315–355 K was observed in the film close to the critical grain size of 21 nm in diameter marked by the transition from single– to multi–domain structure of nanocrystals in Ni0.5Zn0.5Fe2O4 film and by a maximum in its coercivity.

scholarly journals Optical near-field mapping of plasmonic nanostructures prepared by nanosphere lithography

2018 ◽  
Vol 9 ◽  
pp. 1536-1543 ◽  
Author(s):  
Gitanjali Kolhatkar ◽  
Alexandre Merlen ◽  
Jiawei Zhang ◽  
Chahinez Dab ◽  
Gregory Q Wallace ◽  
...  
Keyword(s):  
Numerical Simulations ◽  
Hot Spots ◽  
Near Field ◽  
Nanosphere Lithography ◽  
Plasmonic Nanostructures ◽  
Far Field ◽  
Optical Images ◽  
Spatial Frequencies ◽  
Comparison Of The Results ◽  
Non Destructive

We introduce a simple, fast, efficient and non-destructive method to study the optical near-field properties of plasmonic nanotriangles prepared by nanosphere lithography. Using a rectangular Fourier filter on the blurred signal together with filtering of the lower spatial frequencies to remove the far-field contribution, the pure near-field contributions of the optical images were extracted. We performed measurements using two excitation wavelengths (532.1 nm and 632.8 nm) and two different polarizations. After the processing of the optical images, the distribution of hot spots can be correlated with the topography of the structures, as indicated by the presence of brighter spots at the apexes of the nanostructures. This technique is validated by comparison of the results to numerical simulations, where agreement is obtained, thereby confirming the near-field nature of the images. Our approach does not require any advanced equipment and we suggest that it could be applied to any type of sample, while keeping the measurement times reasonably short.

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