B.B. Vhanakhande, S.V. Jadhav and Vijaya Puri
The purpose of this paper is to compare thick and thin film microstripline response to conducting overlay.
Abstract
Purpose
The purpose of this paper is to compare thick and thin film microstripline response to conducting overlay.
Design/methodology/approach
Study changes in transmission and reflection of both thick and thin film microstripline due to overlay of polyaniline (PANI) thin film on stainless steel and silver. PANI was deposited by electropolymerisation method using HCl and H2SO4.
Findings
Transmittance of both the thick and thin film microstripline decreases due to the PANI overlay and reflectance increases. Thin film microstripline is more sensitive to the type of conducting overlay than thick film microstripline. PANI deposited on silver is more absorbing than PANI deposited on stainless steel using HCl acid. The overlay makes the response of the microstripline more dispersive.
Originality/value
The increase in reflectance and decrease in transmittance can provide information about the type of overlay materials. There is need for newer materials which can replace traditional metals for microstrip components. PANI might serve this purpose.
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The purpose of this paper is to study properties of magnesium oxide and mixed magnesium oxide‐bismuth oxide thick films for application in tuned devices.
Abstract
Purpose
The purpose of this paper is to study properties of magnesium oxide and mixed magnesium oxide‐bismuth oxide thick films for application in tuned devices.
Design/methodology/approach
The effect of magnesium oxide and mixed magnesium oxide‐bismuth oxide thick films overlay of different thickness on Ag thick film microstrip rectangular patch antenna was investigated in the X band (8‐12 GHz). Using Ag thick film microstrip rectangular patch antenna the thick and mixed thick films was characterized by microwave properties such as resonance frequency, amplitude, bandwidth, quality factor and input impedance. Using the resonance frequency the permittivity of magnesium oxide and mixed magnesium oxide‐bismuth oxide thick films was measured.
Findings
Cubic structure of single magnesium oxide and monoclinic structure of bismuth oxide was present in mixed thick film. Also the morphology of single thick films was maintained in mixed thick film of magnesium oxide‐bismuth oxide. Due to overlay magnesium oxide and magnesium oxide‐bismuth oxide mixed thick films, change in resonance frequency shifts towards high frequency end was observed. Dielectric constant of magnesium oxide and mixed magnesium oxide‐bismuth oxide thick film calculated from resonance frequency decreased with increase in thickness.
Originality/value
The microwave properties using Ag thick film microstrip patch antenna due to overlay of magnesium oxide and mixed magnesium oxide‐bismuth oxide thick films have been reported for the first time. Thickness of overlay dependent tuning of the antenna has been achieved.
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P.B. Kashid, D.C. Kulkarni, V.G. Surve and Vijaya Puri
The purpose of this paper is to study thickness dependent variation in microwave properties of the MgxMn(0.9−x)Al0.1Zn0.8Fe1.2O4 (x=0.8, 0.9) thick films and enhancement of power…
Abstract
Purpose
The purpose of this paper is to study thickness dependent variation in microwave properties of the MgxMn(0.9−x)Al0.1Zn0.8Fe1.2O4 (x=0.8, 0.9) thick films and enhancement of power efficiency of Ag thick film EMC patch antenna.
Design/methodology/approach
X‐band microwave properties of the MgxMn(0.9−x)Al0.1Zn0.8Fe1.2O4 (x=0.8, 0.9) thick films were measured by superstrate technique using Ag thick film EMC patch antenna as the resonant element. The complex permittivity and permeability of these thick films were also measured by this technique. The microwave response of the EMC patch, complex permeability and permittivity of Mg0.8Mn0.1Al0.1Zn0.8Fe1.2O4 and Mg0.9Al0.1Zn0.8Fe1.2O4 thick films and their thickness dependency were investigated.
Findings
The XRD patterns reveal the cubic spinel crystal system was obtained for both compositions. The crystallite size obtained was 134.68 nm for Mg0.8Mn0.1Al0.1Zn0.8Fe1.2O4 and 155.99 nm for Mg0.9Al0.1Zn0.8Fe1.2O4 The superstrate technique has been used successfully to evaluate the complex permittivity and permeability of the ferrite thick films in the X band. The EMC patch also show thickness and composition dependent frequency agility and enhancement of power efficiency.
Originality/value
The complex permeability of MgxMn(0.9−x)Al0.1Zn0.8Fe1.2O4 (x=0.8, 0.9) thick films measured by superstrate technique is reported in this paper. The superstrate of MgxMn(0.9−x)Al0.1Zn0.8Fe1.2O4 (x=0.8, 0.9) thick films makes the Ag thick film EMC patch antenna frequency agile and power amplification is obtained.
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Phalesta Toussaint and Cristina Jönsson
The purpose of this chapter is to critically evaluate the development of technological infrastructure and the propensity of Latin America and the Caribbean (LAC) destinations to…
Abstract
Purpose
The purpose of this chapter is to critically evaluate the development of technological infrastructure and the propensity of Latin America and the Caribbean (LAC) destinations to adopt digitalisation in their hotel sectors. This paper focuses on technological readiness, the types of digitalisation and its influence on the hotel sector in a post-pandemic environment.
Design/Methodology/Approach
The chapter is a critical and conceptual overview of digitalisation in the Latin America and the Caribbean hotel sectors, the contribution of the hotel sector to tourism economies, and digitalisation in LAC post COVID-19. A comprehensive examination of the academic literature is combined with the Network Readiness Index (NRI) and Travel and Tourism Competitiveness Index (TTCI) on several LAC countries focusing on different scopes including ICT readiness, ICT environment and business usage from 2010 to 2020. The paper uses empirical data collected from NRI and TTCI on several LAC countries examining changes in development of information and communications technology (ICT) by conducting a longitudinal analysis over a ten-year period.
Findings
The chapter argues that digitalisation in the hotel sector has been given a lot of attention regarding the adoption of digitalisation during the pandemic by a continuation of activities involving check-in and check-out, providing safety for guests and staff and the recovery of the hotel sector by both hoteliers and academics. Yet, LAC have been slow when it comes to the development of ICT. This is shown on the NRI and the TTCI by their position on ICT infrastructure, ICT environment and business usage. Nevertheless, while their positions on the indexes are less than favourable, their scores are improving, but at a very slow rate.
Research Limitation
Limited academic literature is available on digitalisation in LAC countries. There is no consistent data on the NRI and TTCI year to year for some of the countries examined in this study.
Originality/Value
This study provides a comprehensive review of technological infrastructure development of countries of Latin America and Caribbean countries with an emphasis on digitalisation in a hospitality context. The chapter is a critical examination of digitalisation in the hotel sector in a post-pandemic environment.
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S.N. Mathad, R.N. Jadhav and Vijaya Puri
The purpose of this paper was to determine the complex permittivity of bismuth strontium manganites (Bi1−xSrxMnO3) in the 8‐12 GHz range by using perturbation of Ag thick film…
Abstract
Purpose
The purpose of this paper was to determine the complex permittivity of bismuth strontium manganites (Bi1−xSrxMnO3) in the 8‐12 GHz range by using perturbation of Ag thick film microstrip ring resonator (MSRR) due to superstrate of both bulk and thick film.
Design/methodology/approach
The BSM ceramics were synthesized by simple low cost solid state reaction method and their fritless thick films were fabricated by screen printing technique on alumina substrate. A comparison has been made between the X band response of Ag thick film microstrip ring resonator due to perturbation of bulk and thick film Bi1−xSrxMnO3 ceramic.
Findings
The bulk and thick film superstrate decreases the resonance frequency of MSRR. In this technique even minor change in the properties of superstrate material changes the MSRR response. Variation of strontium content also influences microwave conductivity and penetration depth of bulk and thick films.
Originality/value
The microwave complex permittivity decreases with increase in Sr content in bismuth manganite and it is higher for bulk as compared to its thick films. The superstrate on Ag thick film microstrip ring resonator is an efficient tool capable of detecting the composition dependent changes in microwave properties of ceramic bulk and thick films.
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This paper reports the behaviour of a parallel coupled band pass microstrip filterdue to an Al2O3 thin film‐thick film overlay and the effectof the moisture ambient on the…
Abstract
This paper reports the behaviour of a parallel coupled band pass microstrip filter due to an Al2O3 thin film‐thick film overlay and the effect of the moisture ambient on the properties of the overlaid microstrip filter. The thickness of the initial thin‐film overlay affects the behaviour of the filter after thick‐film overlay. Moisture has the effect of lowering the transmittance drastically and shifting the pass band to the lower frequency end. The filter loses its band pass characteristics after a few moisture‐heat cycles, indicating irreversible change taking place in the overlay material. It is felt that the ageing aspects of the overlay material should be taken into account when using dielectric overlays for circuit protection and cross‐over insulation purposes.
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The microwave properties of microstripline at S‐band and X‐band and ?/2 rejection filter with midband rejection at 3 GHz fabricated by thick film technology are studied. The…
Abstract
The microwave properties of microstripline at S‐band and X‐band and ?/2 rejection filter with midband rejection at 3 GHz fabricated by thick film technology are studied. The effect of an overcoat of Ag thin film of thickness 2 µm deposited by ion plating and electroless plating on Ag and Pd‐Ag thick film circuits is reported. There is a drastic improvement in the performance of the thick film circuits after overcoating. This is attributed to the superior edge definition whereby losses are reduced. As the edge is smoother, especially at the coupling area of the filter, there is tighter coupling, thus increasing the Q of the filter. The overcoat may also reduce the large open areas of the thick film, giving a smoother upper surface finish. This type of metallic overcoat, i.e., hybrid of thick and thin film, may reduce the need for costly and time‐consuming functional trimming and expensive thick film materials.
This paper aims to study tuning effects on thick film microstripline due to ferrite thick film overlay.
Abstract
Purpose
This paper aims to study tuning effects on thick film microstripline due to ferrite thick film overlay.
Design/methodology/approach
The possibility of obtaining tuning characteristics in the Ku band microwave region in the absence of external magnetic field by a simple process of using NixZn1−xFe2O4 thick film and bulk as in‐touch overlay over Ag thick film microstripline was investigated. The microstripline is basically a non‐resonant component with high‐transmission at a large microwave frequency band. The ferrite was synthesized by precursor method and the thick films were deposited by screen printing.
Findings
It was found that tuning characteristics were observed and composition, thickness and precursor dependent changes occurred. The changes with composition are more prominent in the 14.5‐16.5 GHz range. Also, the ferrite thick film overlay produces a deep notch at 15.7 GHz. It is observed that the pellet overlay also makes the microstripline very dispersive with a high‐insertion loss in the 16‐17 GHz range. The presence of permeability‐related effects interfering with the normal propagation of the microstrip circuits might be causing the changes in the circuits.
Originality/value
Owing to the NixZn1−xFe2O4 overlay the simple microstripline can be tuned to have narrow band filter type of characteristics. Thick film NixZn1−xFe2O4 overlay gives the added advantage of planer configuration along with cost‐effectiveness in the absence of magnetic field.
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S. Patil and Vijaya Puri
The purpose of this paper is to report the effect of bismuth oxide thick films of various thicknesses on the X band (8‐12 GHz) response of Ag thick film microstrip rectangular…
Abstract
Purpose
The purpose of this paper is to report the effect of bismuth oxide thick films of various thicknesses on the X band (8‐12 GHz) response of Ag thick film microstrip rectangular patch antenna.
Design/methodology/approach
The effect of bismuth oxide thick film overlay of different thickness on Ag thick film microstrip rectangular patch antenna was investigated in the X band (8‐12 GHz). The change in the resonance frequency, amplitude, band width, quality factor, and input impedance of the antenna were studied. Using the resonance frequency the permittivity and conductivity of bismuth oxide thick film was measured.
Findings
Thickness of Bi2O3 thick film overlay dependent changes in the patch antenna characteristics is obtained. The resonance frequency shifts to higher frequency end due to overlay. The input impedance decreases due to the overlay. The dielectric constant of bismuth oxide thick film calculated from shift in resonance frequency shows thickness dependent values.
Originality/value
The microwave permittivity and conductivity of Bi2O3 thick film have been reported for the first time using overlay on thick film patch antenna. Thickness of overlay dependent tuning of the antenna has been achieved.
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Maruti K. Rendale, S.N. Mathad and Vijaya Puri
The present communication aims to investigate the influence of cobalt substitution on the structural, mechanical and elastic properties of nickel–zinc ferrite thick films. The…
Abstract
Purpose
The present communication aims to investigate the influence of cobalt substitution on the structural, mechanical and elastic properties of nickel–zinc ferrite thick films. The changes observed in the crystallite size (D), lattice constant (a), texture coefficient [TC(hkl)] and mechanical and elastic properties of the thick films due to cobalt substitution have been reported systematically.
Design/methodology/approach
Ni–Zn ferrites with the stoichiometric formula Ni0.7−xCoxZn0.3Fe2O4 (where, x = 0, 0.04, 0.08, 0.12, 0.16 and 0.20) were synthesized via solution combustion technique using sucrose as the fuel and poly-vinyl-alcohol as the matrix material. The thick films of the ferrites were fabricated on alumina substrates by the screen printing method. The thickness of the films was 25 μm, as measured by the gravimetric method. The thick films were subjected to X-ray diffraction and Fourier transform infrared spectroscopy.
Findings
The detailed study of variation of lattice parameter (a), sintering density, micro-strain and elastic properties with cobalt (Co+2) substituted was carried out. The remarkable increase in lattice parameter (from 8.369 A° to 8.3825 A°), bulk density and average grain size (69-119 nm) with the cobalt content was due to larger ionic radius of Co2+ compared to Ni2+. Texture analysis [TC(hkl)] reveals all thick films have adequate grain growth in the (311) plane direction. The main absorption bands of spinel ferrite have appeared through infrared absorption spectra recorded in the range of 300-700 cm−1.
Originality/value
The variation in stiffness constants (for isotropic material, C11 = C12), longitudinal elastic wave (Vl), transverse elastic wave (Vt), mean elastic velocity (VMean), rigidity modulus (G), Poisson’s ratio(s) and Young’s modulus (E) with cobalt (Co+2) composition has been interpreted in terms of binding forces found.