| URI: | http://dyuthi.cusat.ac.in/purl/2732 |
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| Dyuthi-P00366.pdf | (129.9Kb) |
| Abstract: | A new design for a compact electronically reconffgurable singlefeed dual frequency dual-polarized operation of a square-microstrip antenna capable of achieving tunable frequency ratios in the range 1.1 to 1.37 is proposed and experimentally studied. Varactor diodes inlegruted with the arms of the hexagonal slot and embedded in the square patch are used to tune the operating frequencies by applying reverse-bias voltage. The design has the advantage of size reduction up to 73.21% and 49.86% for the two resonant frequencies, respectively, as compared to standard rectangular patches. The antenna offers good bandwidth of 5.74% and 5.36% for the two operating frequencies. A highly simplified tuning circuitry without any transmission lines adds to the compactness of the design |
| URI: | http://dyuthi.cusat.ac.in/purl/1424 |
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| Development of ... ble microstrip antenna.PDF | (1.614Mb) |
| Abstract: | A new method for enhancing the 2.1 VSWR impedance bandwidth of microstrip antennas is presented. Bandwidth enhancement is achieved by loading the microstrip antenna by a ceramic microwave dielectric resonator (DR). The validity of this technique has been established using rectangular and circular radiating geometries. This method improves the bandwidth of a rectangular microstrip antenna to more than 10% (= 5 times that of a conventional rectangular microstrip antenna) with an enhanced gain of I dB |
| URI: | http://dyuthi.cusat.ac.in/purl/1367 |
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| Dielecting-reso ... ndwidth and efficiency.PDF | (1.297Mb) |
| Abstract: | Permittivity and conductivity studies of corn syrup in various concentrations are performed using coaxial cavity perturbation technique over a frequency range of 250 MHz–3000 MHz. The results are utilized to estimate relaxation time and dipole moments of the samples. The stability of the material over the variations of time is studied. The measured specific absorption rate of the material complies with the microwave power absorption rate of biological tissues. This suggests the feasibility of using corn syrup as a suitable, cost effective coupling medium for microwave breast imaging. The material can also be used as an efficient breast phantom in microwave breast imaging studies. |
| URI: | http://dyuthi.cusat.ac.in/purl/2738 |
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| Dyuthi-P00372.pdf | (196.2Kb) |
| Abstract: | Phantoms that exhibit complex dielectric properties similar to low water content biological tissues over the electromagnetic spectrum of 2–3 GHz have been synthesized from carbon black powder, graphite powder and polyvinyl-acetate-based adhesive. The materials overcome various problems that are inherent in conventional phantoms such as decomposition and deterioration due to the invasion of bacteria or mold. The absorption coefficients of the materials for various compositions of carbon black and graphite powder are studied. A combination of 50% polyvinylacetate- based adhesive, 20% carbon black powder and 30% graphite powder exhibits high absorption coefficient, which suggests another application of the material as good microwave absorber for interior lining of tomographic chamber in microwave imaging. Cavity perturbation technique is adopted to study the dielectric properties of the material. |
| URI: | http://dyuthi.cusat.ac.in/purl/2736 |
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| Dyuthi-P00370.pdf | (253.3Kb) |
| Abstract: | Experimental studies on a compact dual frequency microstrip antenna are presented. This antenna configuration provides an area reduction of 40% compared to a standard rectangular antenna operating at the same frequency without much degradation of the gain. The antenna structure can be modified to achieve the desired ratio between the two resonant frequencies |
| URI: | http://dyuthi.cusat.ac.in/purl/1375 |
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| Dual-band dual- ... act microstrip antenna.PDF | (907.1Kb) |
| Abstract: | A new design of' a dual-frequency dual-polarized square microsh'ip antenna fed along the diagonal, embedded with a square slot having three extended stubs for frequency tuning, is introduced. The proposed antenna was fabricated using a standard photolithographic method and the antenna was tested using the HP 3510(:; Vector Network Analyser. The antenna is capable of generating dual resonant frequencies with mutually perpendicular polarizations and broad radiation pattern characteristics. Such dual-frequency designs find wide applications in personal mobile handsets combining GSM and CDS 1800 modes, and applications in which different frequencies are used for emission and reception such as personal satellite communications and cellular network systems. |
| URI: | http://dyuthi.cusat.ac.in/purl/1397 |
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| Dual-frequency ... r communication system.PDF | (2.098Mb) |
| Abstract: | Experimental and simulated results for a dual-port dual-polarized microstrip antenna are presented. The antenna excites two orthogonally polarized resonant frequencies providing an isolation of -30 dB between the ports. The patch geometry consists of two circular arcs of different radii with their centers displaced by a distance. This new design offers an area reduction of -70% coinpared to it standard rectangular microstrip antenna with a reduction in gain of 1.7 dB |
| URI: | http://dyuthi.cusat.ac.in/purl/1391 |
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| Dual-band dual- ... act microstrip antenna.PDF | (907.1Kb) |
| Abstract: | A new design of a dual-band dual-polarized electromagnetically coupled slot loaded square patch antenna, covering the WLAN 5.2 GHz and 5.8 GHz bands, achieving bandwidth enhancement by using tapered slot structure, is presented here. The proposed antenna covers 5.09–5.47 GHz and 5.7–5.88 GHz bands. Details of the antenna design along with experimental and simulated results are presented and discussed. |
| URI: | http://dyuthi.cusat.ac.in/purl/2720 |
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| Dyuthi-P00357.pdf | (629.0Kb) |
| Abstract: | In this paper, a dual port, dual frequency, dual polarized, octagonal shaped Microstrip patch antenna, suitable for GPS applications is discussed experimentally and theoretically. The proposed antenna configuration is characterized by good impedance bandwidth, gain, isolation between two ports and broad radiation patterns |
| Description: | Personal Wireless Communications, 2005. ICPWC 2005. 2005 IEEE International Conference on,PP 305-307 |
| URI: | http://dyuthi.cusat.ac.in/purl/4336 |
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| Electromagnetic ... ctagonal Patch Antenna.pdf | (207.5Kb) |
| Abstract: | A theoretical analysis of a symmetric T-shaped rnicrostripfed rectangular microstrip antenna using the finite-difference titnedoniain (FDTD) method is presented in this paper. The resonant frequency, return loss, impedance bandwidth, and radiation patterns are predicted and are in good agreement with the measured results |
| URI: | http://dyuthi.cusat.ac.in/purl/1408 |
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| FDTD analysis o ... lar microstrip antenna.PDF | (850.6Kb) |
| Abstract: | Electromagnetic scattering behaviour of a superstrate loaded metallo– dielectric structure based on Sierpinski carpet fractal geometry is reported. The results indicate that the frequency at which backscattering is minimum can be tuned by varying the thickness of the superstrate. A reduction in backscattered power of 44 dB is obtained simultaneously for both TE and TM polarisations of the incident field. |
| URI: | http://dyuthi.cusat.ac.in/purl/675 |
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| Frequency tunab ... ering reduction Anupam.pdf | (205.4Kb) |
| Abstract: | Negative magnetic permeability media (NMPM) can be built up by using small resonant metallic particles like Split ring resonator (SRR) which has very high magnetic polarisability. A group of these particles shows a negative permeability region near and above the resonant frequency. The continuous medium parameters describing the SRR array can be predicted from their individual electromagnetic behavior near the resonances. The paper presents an optimizing software using Genetic Algorithm (GA) to design an edge coupled two ring SRR for a particular frequency |
| Description: | Recent Advances in Microwave Theory and Applications, 2008. MICROWAVE 2008. International Conference on |
| URI: | http://dyuthi.cusat.ac.in/purl/4345 |
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| Ga Optimized Srr Calculator.pdf | (1.052Mb) |
| Abstract: | A novel technique for backscattering reduction for both TE and TM polarisation, employing a metallo-dielectric structure based on Sierpinski carpet fractal geometry, is reported. A reduction in backscattered power of --30 dB is obtained for normal incidence in the X-band for the structure using the third iterated stage of the fractal geometry |
| URI: | http://dyuthi.cusat.ac.in/purl/1406 |
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| Low backscatter ... d on sierpinski carpet.PDF | (1.096Mb) |
| Abstract: | This paper presents the outcome of the experimental studies performed on L-strip fed compact rectangular microstrip antenna. The effect of the feed parameters upon the characteristics of the antenna is studied in detail. The antenna offers an impedance bandwidth of nearly 20% and is suitable for broadband applications |
| URI: | http://dyuthi.cusat.ac.in/purl/1412 |
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| L-strip excited ... lar microstrip antenna.PDF | (898.2Kb) |
| Abstract: | Design of a compact microstrip band reject filter is proposed. The device consists of an Open Loop Rectangular Resonator (OLRR) coupled to a microstrip line. The transmission line has a U-bend which enhances the coupling with the OLRR element and reduces the size of the filter. The filter can be made tunable by mounting variable capacitance to the system. Simulated and experimental results are presented. |
| URI: | http://dyuthi.cusat.ac.in/purl/2721 |
| Files | Size |
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| Dyuthi-P00358.pdf | (225.0Kb) |
| Abstract: | A phantom that exhibits complex dielectric properties similar to low-water-content biological tissues over the electromagnetic spectrum of 2000–3000 MHz has been synthesized from carbon black, graphite powder, and poly vinyl acetate (PVA)-based adhesive. The material overcomes various problems that are inherent in conventional phantoms such as decomposition and deterioration due to the invasion of bacteria or mold. The absorption coefficients of the material for various concentrations of carbon and graphite are studied. A combination of 50% poly-vinyl-acetate-based adhesive, 20% carbon, and 30% graphite exhibits a high absorption coefficient, which suggests another application of the material as a good microwave absorber for the interior lining of tomographic chamber in microwave imaging. The cavity-perturbation technique is adopted to study the dielectric properties of the material. |
| URI: | http://dyuthi.cusat.ac.in/purl/2734 |
| Files | Size |
|---|---|
| Dyuthi-P00368.pdf | (140.7Kb) |
| Abstract: | A circular miqrostrip antenna with a modified structure is presented. By adjusting the feed location along the circumference of the patch it is possible to match the antenna with a C microstrip line of any impedance. The impedance bandwidth and radiation characteristics are unaffected by this structural V modification. |
| URI: | http://dyuthi.cusat.ac.in/purl/674 |
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| Modified circular patch antenna Dey.pdf | (199.5Kb) |
| Abstract: | A simple technique to improve the impedance bandwidth of a circular microstrip patch antenna using two sectorial slots is proposed. Using this design more than 5% impedance bandwidth is obtained. The added advantage of this new antenna is that it can be fed by a 50- microstrip line |
| URI: | http://dyuthi.cusat.ac.in/purl/1366 |
| Files | Size |
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| A new broadband circular patch antenna.PDF | (1.429Mb) |
| Abstract: | A simple technique to improve the impedance bandwidth of a circular microstrip patch antenna using two sectorial slots is proposed. Using this design more than 5% impedance bandwidth is obtained. The added advantage of this new antenna is that it can be fed by a 50 microstrip line. |
| URI: | http://dyuthi.cusat.ac.in/jspui/handle/dyuthi/1558 |
| Files | Size |
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| A new broadband circular patch antenna.PDF | (1.429Mb) |
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