scholarly journals High Q Dielectric Titanium Tellurite Thick Films on Alumina Substrates for High Frequency Telecommunications

Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 467
Author(s):  
Xinming Su ◽  
Alexander Tkach ◽  
Jerzy Krupka ◽  
Paula M. Vilarinho
Keyword(s):  
High Frequency ◽  
Low Cost ◽  
Thick Films ◽  
Microwave Dielectric Properties ◽  
Carbon Layer ◽  
Vital Role ◽  
Transport Systems ◽  
High Q ◽  
Satellite Broadcasting ◽  
Quality Factor Q

The vital role of high-quality-factor (Q) high-frequency (f) dielectric resonators in the growing microwave telecommunication, satellite broadcasting and intelligent transport systems has long motivated the search for new, small size, and lightweight integrated components and packages, prepared by low cost and sustainable processes. One approach is replacing the currently used bulk ceramic dielectrics by thick films of low-sintering-temperature dielectrics fabricated by affordable processes. Here we demonstrate the fabrication of high-Q TiTe3O8 thick films directly on low loss Al2O3 substrates by electrophoretic deposition using sacrificial carbon layer. Nineteen-micrometre-thick TiTe3O8 films on Al2O3 sintered at 700 °C are found to have a relative permittivity εr of 32 and Q × f > 21,000 GHz. Being thus able to measure and provide for the first time the microwave dielectric properties of these films, our results suggest that TiTe3O8 films on Al2O3 substrates are suitable for microlayer microstrip array applications.

scholarly journals Progress of Waveguide Ring Resonators Used in Micro-Optical Gyroscopes

Photonics ◽  
2020 ◽  
Vol 7 (4) ◽  
pp. 96
Author(s):  
Zuo Feng ◽  
Yuming He ◽  
Wei Yan ◽  
Fuhua Yang ◽  
Weihua Han ◽  
...  
Keyword(s):  
Calcium Fluoride ◽  
Ring Resonator ◽  
Low Cost ◽  
Ring Resonators ◽  
High Q ◽  
Double Ring ◽  
Integration Density ◽  
Density Values ◽  
Waveguide Ring ◽  
Quality Factor Q

Micro-optical gyroscopes (MOGs) are a type of high-accuracy gyroscope, which have the advantages of miniaturization, low cost, and satisfactory operating power. The quality factor (Q) of the waveguide ring resonators (WRRs) is very important to the performance of MOGs. This paper reviews various MOGs using WRRs made from different materials, including silica, indium phosphide, calcium fluoride, and polymer WRRs. The different architectures of the MOGs are reviewed, such as double-ring resonator MOGs and multiple-ring resonator MOGs. Candidate high-Q WRRs for MOGs, including silicon nitride, lithium niobite, calcium fluoride, and magnesium fluoride WRRs, are also reviewed. The manufacturing process, Q, and integration density values are compared. Summarizing the advanced WRRs and calculating the shot-noise-limited sensitivity are helpful processes in selecting suitable materials to fabricate MOGs.

scholarly journals Comparison of Different Large Signal Measurement Setups for High Frequency Inductors

Electronics ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 691
Author(s):  
Jaime Lopez-Lopez ◽  
Cristina Fernandez ◽  
Andrés Barrado ◽  
Pablo Zumel
Keyword(s):  
Power Supply ◽  
High Frequency ◽  
Frequency Range ◽  
Good Match ◽  
Large Signal ◽  
Systematic Analysis ◽  
High Q ◽  
On Chip ◽  
Quality Factor Q

The growing interest of miniaturized power converters has pushed the development of high frequency inductors integrated in Power Supply on Chip or Power Supply in Package. The proper characterization of inductor impedance is a challenge due to the dependence of the impedance on the current, the high quality factor (Q) and the high frequency range where these devices operate. In this paper, we present a comparison of different measuring methods to characterize high frequency and high Q inductors. The comparison is based on a systematic analysis of the measurement process, quantifying the influence of the parameters that affect the measurement result. Four common measurement setups are analyzed and compared. To validate the calculations, the resistance of a high frequency, high-Q inductor is characterized using every presented setup. The good match between calculations, simulation and measurement validates the analysis and the conclusions extracted.

scholarly journals Microstructure and Thermoelectric Properties of (Bi0.48Sb1.52)Te3 Thick Films Prepared with Tape Casting Method

Electronics ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 140
Author(s):  
Lichen Liu ◽  
Ziping Cao ◽  
Min Chen ◽  
Jun Jiang
Keyword(s):  
Thermoelectric Properties ◽  
Low Cost ◽  
Thick Films ◽  
Tape Casting ◽  
Casting Process ◽  
Casting Method ◽  
Glass Substrates ◽  
Conductive Films ◽  
Casting Technology

This paper reports the fabrication and characterization of (Bi0.48Sb1.52)Te3 thick films using a tape casting process on glass substrates. A slurry of thermoelectric (Bi0.48Sb1.52)Te3 was developed and cured thick films were annealed in a vacuum chamber at 500–600 °C. The microstructure of these films was analyzed, and the Seebeck coefficient and electric conductivity were tested. It was found that the subsequent annealing process must be carefully designed to achieve good thermoelectric properties of these samples. Conductive films were obtained after annealing and led to acceptable thermoelectric performance. While the properties of these initial materials are not at the level of bulk materials, this work demonstrates that the low-cost tape casting technology is promising for fabricating thermoelectric modules for energy conversion.

scholarly journals A Low-cost System for High-frequency Solar Imagery and Power Data Acquisition

2021 ◽  
Vol 1826 (1) ◽  
pp. 012082
Author(s):  
G F Bassous ◽  
R F Calili ◽  
C R H Barbosa
Keyword(s):  
Data Acquisition ◽  
High Frequency ◽  
Low Cost ◽  
Cost System

Microstructure and Microwave Dielectric Properties of BaTi4O9 Ceramics Derived from a Sol-Gel Precursor

2011 ◽  
Vol 326 ◽  
pp. 127-130
Author(s):  
Xian Li Huang ◽  
Fu Ping Wang ◽  
Ying Song
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Dielectric Loss ◽  
Sol Gel ◽  
Microwave Dielectric Properties ◽  
Sintering Process ◽  
Temperature Coefficients ◽  
Microwave Dielectric ◽  
Ceramic Samples ◽  
Quality Factor Q

In the present work, the microstructure and microwave dielectric properties of BaTi4O9 ceramics derived from a sol-gel precursor were presented. Density measuring results demonstrated that the largest densities of ceramic sample about 96.7% could be reached by virtue of a cool iso-static press and a sintering process at at 1300 °C for 6 hours. The dielectric constant (εr), quality factor (Q×f) and the temperature coefficients (τf) of the BaTi4O9 ceramic samples were 36.65, 28000 GHz, +20.2 ppm/°C, respectively. XRD, SEM and XPS were used to characterize the microstructure of the ceramics samples. Substantial Ti3+ was proposed to be the cause of dielectric loss.

Photocatalytic Degradation of Synthetic Sulfur Pollutants in Petroleum Fractions under Different pH and Photocatalyst

2021 ◽  
Vol 02 (01) ◽  
Author(s):  
Mohamad Alif Hakimi Hamdan ◽  
◽  
Nur Hanis Hayati Hairom ◽  
Nurhafisza Zaiton ◽  
Zawati Harun ◽  
...  
Keyword(s):  
Photocatalytic Degradation ◽  
Zno Nanoparticles ◽  
Low Cost ◽  
Industrial Effluents ◽  
Degradation Process ◽  
Vital Role ◽  
Petroleum Fraction ◽  
Precipitation Method ◽  
Synthesis Process ◽  
Petroleum Fractions

Thiophene is one of the sulfur compounds in the petroleum fraction that can be harmful to living things and lead to a critical effect on the ecosystem. Photocatalytic degradation is one of the promising methods in treating wastewater as it can mineralization of pollutants into carbon dioxide and water. Other than that, this method is non-toxic and relatively low cost. The production of hydroxyl radicals playing a vital role in the degradation of organic pollutants. It has been claimed that the usage of zinc oxide (ZnO) nanoparticles could give an excellent degradation process as this photocatalyst have high photosensitivity, low cost and chemically stable. However, the preparation method of ZnO nanoparticles will affect the agglomeration, particle size, shape and morphology of particles and lead to influence the photocatalytic activity in degrading thiophene. Therefore, this study focused on the effectiveness of ZnO nanoparticles in the presence of fibrous nanosilica (KCC-1) and polyethylene glycol (PEG) as the capping agent to degrade synthetic thiophene. ZnO/KCC-1 had been synthesized via the precipitation method and characterized by using Fourier Transform Infrared (FTIR). The chemical bond and nature of the photocatalyst from the FTIR results proved that the synthesis process to produce the ZnO/KCC-1 was succeed. The large surface area of KCC-1 increases the effectiveness of ZnO which is supported by the experimental data. Accordingly, the optimum condition for photocatalytic degradation of thiophene is under pH 7 by using ZnO/KCC-1 as photocatalyst. Hence, it is believed that this research could be implemented to remove the thiophene in petroleum fraction from the actual industrial effluents and this can preserve nature in the future.

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