scholarly journals Radiowave technology of resonant gas-sensor microwave telemetry

2021 ◽  
Vol 9 (1) ◽  
pp. 18-28
Author(s):  
M. S. Kostin ◽  
A. D. Yarlykov
Keyword(s):  
Dielectric Constant ◽  
Reflection Coefficient ◽  
Gas Sensor ◽  
Resonance Region ◽  
Effective Area ◽  
Dielectric Substrate ◽  
Substrate Material ◽  
Gas Analysis ◽  
Microstrip Resonator ◽  
Microwave Resonators

The possibility of using microstrip reflector microwave resonators in solving problems of resonant gas-sensor telemetry on layered dielectric substrates with gas-sensitive sputtering was investigated. It is noted that the use of chemically active sputtering, for example, on the basis of zeolites having a high selective gas adsorbent kinetics in terms of speed, makes it possible to create radiosensor materials capable of changing the dielectric constant in the process of absorbing gases, as well as of sublimated vapors of solid and liquid phases of various compounds. As an alternative approach in the field of dosimetric gas monitoring, a modification of radiosensor applications based on microwave sensors is proposed, which allows using microwave solutions based on microstrip microwave resonators with active gas-sensitive sorption zeolite sputtering on a dielectric substrate to conduct gas analysis in real time. The radio-wave principle of the microstrip gas sensor analyzer was formulated. An electrodynamic model of a microstrip gas sensor analyzer in the Altair Feko environment was developed. An experiment was planned, and gas-sensor telemetry tests of ammonia vapors  dissolved  in  water were carried out. It was established that the amount  of sorbed water and ammonia in the zeolite unambiguously conforms both to the absolute value of the reflection coefficient at resonance and to the resonant frequency itself. Using  the example of recording hydrogen nitride vapors it was shown that the reflection coefficient and frequency shift in the resonator, which depend on the concentration of the adsorbed gas, correspond to the saturation characteristics of the gas sensor and make it possible to repeatedly measure small concentrations of a gas that can be absorbed by zeolite at a temperature corresponding to the condition of rapid evaporation of controlled gas from the active dielectric layer, which guarantees desorption of the sensor. It was established that in order to increase the speed of the gas sensor response it is advisable to create a microstrip resonator for the resonance region of 8...10 GHz and to use a microstrip sensor substrate material with a high dielectric constant. This is due to the fact that the transition to the upper microwave frequencies will allow reducing the size of the topology of the microstrip resonator and reducing the effective area of the zeolite deposition, and, consequently, increasing the adsorption rate of the gas-sensitive layer of the active dielectric.

Fan Shaped Patch with Fan Shaped Defected Ground Structure is designed for X-band Applications

2018 ◽  
Vol 8 (4) ◽  
pp. 57
Author(s):  
K.S. Ravi Kumar ◽  
Lalbabu Prasad ◽  
B. Ramesh ◽  
K.P. Vinay
Keyword(s):  
Dielectric Constant ◽  
Low Cost ◽  
Dielectric Substrate ◽  
Substrate Material ◽  
Frequency Range ◽  
Defected Ground Structure ◽  
Ground Structure ◽  
Band Region ◽  
X Band ◽  
Simulation Results

In this novel work a simple Fan Shaped Patch (FSP) Antenna is designed for X-band applications using Fan Shaped DGS structure to improve the Bandwidth and Gain. The Antenna is designed by using low cost FR4 Epoxy dielectric substrate material having dielectric constant of 4.4 with size 31.4x28.33x1.6mm3. The Antenna is simulated by using CST MW studio2014 software to analyze the results. The simulation results shows reasonable |S11|<-10 for the frequency range over 8.38 to 11.59GHz in X-band region.

Microstructural characterization of YBaCuO Films on LaAlO3 substrates

1989 ◽  
Vol 47 ◽  
pp. 180-181
Author(s):  
E. L. Hall ◽  
A. Mogro-Campero ◽  
N. Lewis ◽  
L. G. Turner
Keyword(s):  
Dielectric Constant ◽  
Single Crystal ◽  
Film Growth ◽  
Microstructural Characterization ◽  
Lattice Parameter ◽  
Film Plane ◽  
Substrate Material ◽  
High Loss ◽  
Amorphous Substrates ◽  
High Dielectric

There have been a large number of recent studies of the growth of Y-Ba-Cu-O thin films, and these studies have employed a variety of substrates and growth techniques. To date, the highest values of Tc and Jc have been found for films grown by sputtering or coevaporation on single-crystal SrTiO3 substrates, which produces a uniaxially-aligned film with the YBa2Cu3Ox c-axis normal to the film plane. Multilayer growth of films on the same substrate produces a triaxially-aligned film (regions of the film have their c-axis parallel to each of the three substrate <100> directions) with lower values of Jc. Growth of films on a variety of other polycrystalline or amorphous substrates produces randomly-oriented polycrystalline films with low Jc. Although single-crystal SrTiO3 thus produces the best results, this substrate material has a number of undesireable characteristics relative to electronic applications, including very high dielectric constant and a high loss tangent at microwave frequencies. Recently, Simon et al. have shown that LaAlO3 could be used as a substrate for YBaCuO film growth. This substrate is essentially a cubic perovskite with a lattice parameter of 0.3792nm (it has a slight rhombohedral distortion at room temperature) and this material exhibits much lower dielectric constant and microwave loss tangents than SrTiO3. It is also interesting from a film growth standpoint since it has a slightly smaller lattice parameter than YBa2Cu3Ox (a=0.382nm, b=c/3=0.389nm), while SrTiO3 is slightly larger (a=0.3905nm).

The kinetic semiconductor gas-sensor conduction model and its practical use in gas analysis

1993 ◽  
Vol 14 (1-3) ◽  
pp. 687-689 ◽  
Author(s):  
E.Ye. Gutman ◽  
I.A. Myasnikov ◽  
S.A. Kazakov ◽  
S.V. Rugentsev ◽  
S.K. Dymenko
Keyword(s):  
Gas Sensor ◽  
Gas Analysis ◽  
Conduction Model ◽  
Semiconductor Gas Sensor

Identification of Water Molecules in Low Humidity and Possibility of Quantitative Gas Analysis using Porous Silicon Gas Sensor

1996 ◽  
Vol 35 (Part 1, No. 8) ◽  
pp. 4253-4256 ◽  
Author(s):  
Akira Motohashi ◽  
Masatoshi Ruike ◽  
Manabu Kawakami ◽  
Hidekazu Aoyagi ◽  
Akira Kinoshita ◽  
...  
Keyword(s):  
Porous Silicon ◽  
Gas Sensor ◽  
Gas Analysis ◽  
Water Molecules ◽  
Low Humidity

Preparation and Electromagnetic Properties of Al2O3/Ni Composites

2014 ◽  
Vol 602-603 ◽  
pp. 926-930
Author(s):  
Zhi Xue Qu ◽  
Qun Wang ◽  
Bin Pang ◽  
Xue Cheng Hou ◽  
Wei Pan
Keyword(s):  
Dielectric Constant ◽  
Electromagnetic Compatibility ◽  
Sintering Temperature ◽  
Substrate Material ◽  
Electromagnetic Properties ◽  
Ni Content

In this paper, a series of Al2O3/Ni composites with various content of Ni (0 vol%, 10 vol%, 20 vol%, 30 vol%, 40 vol% and 50 vol%) were prepared, and the effect of the methods and compositions on the density and electromagnetic properties was investigated. The results show that the density of the composites increases with the increasing sintering temperature as well as the increasing content of Ni. Moreover, the dielectric constant of the composites increases remarkably with the sintering temperature and the content of Ni, while the permeability shows an almost linear enhancement with the increase of Ni content. This suggests that the Al2O3/Ni composite can be expected to be a promising substrate material with certain electromagnetic compatibility.

scholarly journals Formation of Fractal Antenna Array for Multiband Applications

2019 ◽  
Vol 8 (4) ◽  
pp. 3257-3263
Keyword(s):  
Wireless Communication ◽  
Antenna Array ◽  
Microstrip Antenna ◽  
Dielectric Substrate ◽  
High Gain ◽  
Substrate Material ◽  
Vital Role ◽  
Fractal Antenna ◽  
Self Similarity ◽  
Wireless Applications

Antennas play a vital role in wireless communication; a thirst of excellence in this area is unending. Proposed work describes a concept of fractal multiband antenna designed in the hexagon shape. Basically fractal is the concept used in Microstrip antenna for giving better results than conventional Microstrip antenna. By using hexagonal fractal antenna we can possibly achieve the radiation pattern with high gain. The coaxial feeding is used and multiple hexagons are interconnected in array for maintaining conductivity and to preserve electrical self similarity. Hexagonal antenna is used for different wireless applications. The proposed antenna frequency band covers a large number of wireless communication applications including GPS (1.6GHz), Bluetooth (2.4 GHz) & WLAN (3.6GHz). Antenna design has been designed and simulated by using the software Ansoft’s HFSS and parameters like bandwidth return loss, directivity, VSWR are analyzed. Fabrication of the antenna is done by using wet-etching method, on FR-4 dielectric substrate material. Experimental results are taken on Vector Network Analyzer (VNA) and those obtained results were compared with simulated results. The hexagonal fractal antenna array is found to possess predictable multiband characteristics.

A Hammer Type Textile Antenna With Partial Circle Ground for Wide-Band Application

2020 ◽  
pp. 15-24
Author(s):  
Anurag Saxena ◽  
Bharat Bhushan Khare
Keyword(s):  
Dielectric Constant ◽  
Reflection Coefficient ◽  
Patch Antenna ◽  
Wide Band ◽  
Simulation Tool ◽  
Textile Antenna ◽  
Partial Circle ◽  
Maximum Directivity

In this chapter, a partial circle ground textile patch antenna for wideband applications with better bandwidth is presented. The simulated antenna is proposed on textile jeans substrate having dielectric constant of 1.7. The radius of textile jeans substrate antenna is 15 mm. The overall simulation of partial circle grounded shaped antenna has been done using CST simulation tool. The simulated antenna resonates at frequency 9.285 GHz with the reflection coefficient of -28 dB. It covers a bandwidth from 7.008 GHz to 9.64 GHz. It has maximum directivity of 4.540 dBi.

Modified Organic low-k Dielectric Layers on Fired LTCC Substrates

2012 ◽  
Vol 2012 (CICMT) ◽  
pp. 000394-000399
Author(s):  
Achim Bittner ◽  
Ulrich Schmid
Keyword(s):  
Dielectric Constant ◽  
Film Thickness ◽  
High Surface ◽  
Relative Dielectric Constant ◽  
Compound Layer ◽  
Substrate Material ◽  
Filler Material ◽  
Filler Concentration ◽  
Rotating Speed ◽  
S Parameter

In this study, the reduction of permittivity of LTCC substrates by coating with a polyimide compound containing hollow glass microspheres as filler material is described. By incorporating the filler material, the dielectric constant of the substrate material is locally lowered to improve the high-frequency performance of antennas operated in the GHz range. Furthermore, by adding the filler material to the liquid polyimide precursor the layer thickness is heightened from maximum 10 μm to above 80 μm which is enough to fill cavities in LTCC substrates. Two compound materials with filler to polymer ratios 1:7.5 and 1:10 are mixed. Afterwards they are deposited by spin coating onto LTCC substrates. The film thickness depends on the rotating speed and the filler content. With the higher filler concentration and low rotating speed of 500 rpm 82 μm thick polymer films can be achieved. The high surface roughness can be reduced afterwards by adding additional pure polyimide layers on top to Ra= 3 μm. The dielectric constant of the entire substrate consisting of the LTCC and the resulting compound material is measured using a ring resonator in microstrip configuration. From the resonances occurring in the transmission S-parameter |S21| spectrum between 1 to 10 GHz, the relative dielectric constant can be determined. Using 820 μm thick LTCC substrates a relatively low reduction from εr = 7.8 to 6.6 is achieved. However, due to permittivity can be reduced with higher microsphere amounts, the dielectric constant of pure polyimide of εr= 3.3 can also be reduced. Furthermore due to the sufficiently high film thickness of the modified substrates, the compound layer can be used as single dielectric layer.

Characterization of Ultra-Thin Epoxy-Resin Based Dielectric Substrate for Flexible Power Electronics Applications

2017 ◽  
Vol 2017 (1) ◽  
pp. 000151-000156 ◽  
Author(s):  
Xin Zhao ◽  
K. Jagannadham ◽  
Wuttichai Reainthippayasakul ◽  
Michael T. Lanagan ◽  
Douglas C. Hopkins
Keyword(s):  
Thermal Conductivity ◽  
Epoxy Resin ◽  
Power Electronics ◽  
Flexible Electronics ◽  
Dielectric Material ◽  
Dielectric Substrate ◽  
Substrate Material ◽  
Superior Performance ◽  
Wearable Electronics ◽  
Power Module

Abstract Available substrate materials for power module applications has been investigated for a long time. Though Direct Bonded Copper (DBC) substrates, nowadays, have been widely applied in power electronics applications, especially power modules, due to its superior performance in mechanical ruggedness, thermal conductivity, and isolation capability. Its cost and complicated requirements during fabrication processes are always concerns in industries. At the same time, flexible electronics has become a rapidly expanding area with commercial applications including displays, medical, automotive, sensors arrays, wearable electronics, etc. This paper will initiate an investigation on a dielectric material that has potential in high power wearable electronics applications. A recently developed ultra-thin Epoxy-Resin Based Dielectric (ERBD) substrate material which is suitable for power electronic applications, is introduced. The ERBD can be fabricated with thickness as low as 80μm, with more than 5kV DC isolation capability. Its thermal conductivity is 8W/mK, higher than similar product currently available in the market. ERBD is also able to be bonded with Cu plates on both sides. In this paper, the properties of ERBD are investigated. Scanning Electron Microscope (SEM) is applied to analyze the microstructure of ERBD, and its bonding interface with Cu plates. 3-omega and Transient Thermal Reflectance methods are employed to precisely measure the thermal conductivity. Dielectric constant and loss are measured at different frequency. Simulations are applied to correct the error from the fringing effect during the measurement. The leakage current of ERBD is also measured under different voltage and temperature with DC and AC condition. Reliability tests are conducted to examine the electrical isolation and shearing strength of ERBD. The suitability of ERBD for potential flexible power electronics application is discussed based on the results from investigation of properties of the dielectric.

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