Search results

1 – 10 of over 1000
Article
Publication date: 26 April 2013

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.

Details

Microelectronics International, vol. 30 no. 2
Type: Research Article
ISSN: 1356-5362

Keywords

Article
Publication date: 20 January 2012

Shital Patil and Vijaya Puri

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.

Article
Publication date: 11 May 2010

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.

Details

Microelectronics International, vol. 27 no. 2
Type: Research Article
ISSN: 1356-5362

Keywords

Article
Publication date: 3 August 2010

D.C. Kulkarni and Vijaya Puri

The aim of this paper is to investigate microwave Ku band absorbance, complex permittivity, and permeability of SrFe12O19 thick films by a simple and novel waveguide technique.

Abstract

Purpose

The aim of this paper is to investigate microwave Ku band absorbance, complex permittivity, and permeability of SrFe12O19 thick films by a simple and novel waveguide technique.

Design/methodology/approach

The glass frit free or fritless strontium hexaferrite thick films were formulated on alumina by screen printing technique from the powder synthesized by chemical co precipitation method for pH 11 adjusted during the reaction. The 13‐18 GHz frequency band microwave absorbance of the SrFe12O19 thick films by a simple waveguide method. The complex permittivity and permeability of strontium hexaferrite thick films was measured by voltage standing wave ratio technique.

Findings

SrFe12O19 thick films show high ∼80 percent absorbance in the whole 13‐18 GHz frequency band. The thickness dependant microwave properties of strontium hexaferrite thick films were observed. The real permittivity ε′ lies in between eight and 35 with the variation in thickness of the thick film SrFe12O19. The real microwave permeability μ′ of strontium hexaferrite thick films lies in the range 1.12‐6.41. The resonance type behavior was observed at frequency 14.3 GHz. The SrFe12O19 thick film of thickness 30 μm could be a wide band (∼5,000 MHz) absorber with absorbance ∼87 percent for the whole 13‐18 GHz frequency band.

Originality/value

The complex permeability of strontium hexaferrite thick films was measured by simple novel waveguide method. The high absorbance (∼87 percent) of thick film SrFe12O19 over a broad band ∼5,000 MHz will be useful in achieving RAM coatings required for 13‐18 GHz frequency band.

Details

Microelectronics International, vol. 27 no. 3
Type: Research Article
ISSN: 1356-5362

Keywords

Article
Publication date: 10 May 2011

R.N. Jadhav and Vijaya Puri

The purpose of this paper is to describe the use of copper‐substituted nickel manganite thick film and bulk ceramic superstrate on Ag thick film microstrip straight resonator…

Abstract

Purpose

The purpose of this paper is to describe the use of copper‐substituted nickel manganite thick film and bulk ceramic superstrate on Ag thick film microstrip straight resonator (MSR), to modify its response and measure complex permittivity as a function of copper.

Design/methodology/approach

The glass frit free (fritless) copper‐substituted nickel manganite thick films were formulated on alumina substrate by screen printing technique from the powder synthesized by oxalic precursor method. A comparison has been made between the X band response of Ag thick film MSR due to perturbation of bulk and thick film Ni(1−x)CuxMn2O4 (0≤x≤1) ceramic. The shift has been used to measure the permittivity of the ceramic. The dielectric constants obtained by superstrate technique on Ag thick film microstrip component are comparable to those obtained from theoretical calculations.

Findings

The resonance frequency of MSR shifts towards lower frequency due to the presence of Ni(1−x)CuxMn2O4 (0≤x≤1) ceramic as superstrate. The dielectric constant of bulk and thick film match well with the theoretical values. The dielectric constant increases with copper concentration and shows reduction of power gain of MSR. The peak output (power gain) of MSR due to thick film NiMn2O4 increases by 10.19 per cent with decrease in bandwidth and increase in the quality factor with copper concentration.

Originality/value

The superstrate on Ag thick film straight resonator is an efficient tool capable of detecting the composition‐dependent changes in microwave properties of ceramic thick films. These Ni(1−x)CuxMn2O4 ceramic being thermistor materials apart from modifying the response can also be used as power sensors providing cost‐effective miniaturization.

Details

Microelectronics International, vol. 28 no. 2
Type: Research Article
ISSN: 1356-5362

Keywords

Article
Publication date: 31 July 2007

U.B. Lonkar and Vijaya Puri

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.

Details

Microelectronics International, vol. 24 no. 3
Type: Research Article
ISSN: 1356-5362

Keywords

Article
Publication date: 1 February 1986

M.S. Setty

Thick film technology is increasingly used in hybrid microelectronic circuits throughout the world. It is entering areas of electronics hitherto dominated by other technologies…

Abstract

Thick film technology is increasingly used in hybrid microelectronic circuits throughout the world. It is entering areas of electronics hitherto dominated by other technologies. Materials are the most important parameter in any technological development. A single material can generate several technologies (e.g., silicon). The role of a Materials Scientist, particularly in the case of Thick Film Materials, has to be very comprehensive. A ‘Vertical Integration System’ is followed in the study and development of thick film materials. This has helped in understanding the complex reactions taking place and in rectifying the defects formed during thick film processing. It has been amply rewarded during the development of several conducting and resistive materials and while carrying out the basic studies of other materials as thick films. Some future trends in this area have been suggested for adapting this fascinating thick film technology.

Details

Microelectronics International, vol. 3 no. 2
Type: Research Article
ISSN: 1356-5362

Article
Publication date: 18 January 2013

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.

Details

Microelectronics International, vol. 30 no. 1
Type: Research Article
ISSN: 1356-5362

Keywords

Article
Publication date: 2 January 2007

O.S. Aleksić, B.M. Radojčić and R.M. Ramović

The paper aims to focus on thick film planar thermistors.

Abstract

Purpose

The paper aims to focus on thick film planar thermistors.

Design/methodology/approach

Thick film planar thermistors such as rectangular, sandwich, multilayer, segmented and interdigitated were printed of law temperature NTC paste called NTC 3K3 95/2 (Ei Iritel). Their resistivity was measured at room temperature as a function of volume resistivity variations due to electrode effect (diffusion of PdAg into NTC layer) and variation of geometrical parameters such as length l, width w, thickness d, number of segments n. The experimental data obtained were used in forming a model by the simple fitting procedure for counting diffusion effect on volume resistivity and resistivity dependence on geometrical parameters.

Findings

Thermal behavior of NTC thick films was measured in the range of −30‐120°C. Exponential factor B was fitted for measured values and included in the proposed thick film thermistors model. The agreement of measured and calculated data enables simulation of new thermistor geometries.

Originality/value

The paper focuses on the experiment which was the first step in forming a total physical/mathematical model proposed for thick film thermistor resistivity.

Details

Microelectronics International, vol. 24 no. 1
Type: Research Article
ISSN: 1356-5362

Keywords

Article
Publication date: 5 May 2015

Busi Rambabu and Y. Srinivasa Rao

The purpose of this paper is to study high-voltage interactions in polymer thick-film resistors, namely, polyvinyl chloride (PVC)-graphite thick-film resistors, and their…

Abstract

Purpose

The purpose of this paper is to study high-voltage interactions in polymer thick-film resistors, namely, polyvinyl chloride (PVC)-graphite thick-film resistors, and their applications in universal trimming of these resistors.

Design/methodology/approach

The authors applied high voltages in the form of pulses and impulses of various pulse durations and with different amplitudes to polymer thick-film resistors and observed the variation of resistance of these resistors with high voltages.

Findings

The paper finds that high voltages can be used for trimming of polymer thick-film resistors in both directions, i.e. upwards and downwards.

Research limitations/implications

The research implication of this paper is that polymer thick-film resistors can be trimmed downwards or upwards practically using this method.

Practical implications

The practical implications of this paper is that one can trim the polymer thick-film resistors, namely, PVC–graphite thick-film resistors, in both directions, i.e. upwards and downwards, by using this method.

Originality/value

The value of the paper is in showing that high voltages can be used to trim downwards and also upwards in the case of polymer thick-film resistors. This type of trimming is called universal trimming, developed first time for polymer thick-film resistors.

Details

Microelectronics International, vol. 32 no. 2
Type: Research Article
ISSN: 1356-5362

Keywords

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