Now showing items 1-20 of 145
Next Page| Abstract: | The MgAl2O4 ceramics were prepared by the conventional solid-state ceramic route and the dielectric properties studied in the microwave frequency region (3–13 GHz). The phase purity and crystal structure were identified using the X-ray diffraction technique. The MgAl2O4 spinel ceramics show interesting microwave dielectric properties (εr = 8.75, Qux f = 68 900 GHz (loss tangent = 0.00017 at 12.3 GHz), τf =−75 ppm/◦C). The MgAl2O4 has high negative τf, which precludes its immediate use in practical applications. Hence the microwave dielectric properties of MgAl2O4 spinels were tailored by adding different mole fractions of TiO2. The εr and Q factor of the mixed phases were increased with the molar addition of TiO2 into the spinel to form mixtures based on (1−x)MgAl2O4-xTiO2 (x = 0.0−1.0). For x = 0.25 in (1−x)MgAl2O4-xTiO2, the microwave quality factor reaches a maximum value of Qux f = 105 400 GHz (loss tangent = 0.00007 at 7.5 GHz) where εr and τf are 11.035 and −12 ppm/◦C, respectively. The microwave dielectric properties of the newly developed 0.75MgAl2O4-0.25TiO2 dielectric is superior to several commercially available low loss dielectric substrates. |
| URI: | http://dyuthi.cusat.ac.in/purl/519 |
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| APA3282.pdf | (689.8Kb) |
| Abstract: | An asymmetric coplanar strip (ACS) fed dual band F-shaped antenna covering the 2.4/5.2 GHz WLAN bands is presented. The optimized dimensions of the proposed uniplanar antenna are 21 mm × 19 mm when printed on a substrate of dielectric constant 4.4 and height 1.6 mm. The dual band nature of the antenna is brought about by the various current paths in the F-shaped structure and the ground plane. The antenna exhibits nearly omnidirectional radiation characteristics and moderate gain in both the operating bands. Details of the antenna design, simulation, and experimental results are presented and discussed. |
| URI: | http://dyuthi.cusat.ac.in/purl/2718 |
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| Dyuthi-P00356.pdf | (416.5Kb) |
| Abstract: | A dual-port dual-polarized compact microstrip antenna for avoiding cross coupling between the two frequency bands is proposed and analyzed. This antenna offers channel isolation better than 25 dB, and is more compact compared to a conventional rectangular patch. Analytical equations for calculating the resonant frequencies at both ports are also presented. The theoretical calculations are verified using experimental results |
| URI: | http://dyuthi.cusat.ac.in/purl/1393 |
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| Analysis and de ... act microstrip antenna.PDF | (1.268Mb) |
| Abstract: | A new compact microstrip antenna element is analyzed. The analysis can accurately predict the resonant frequency, input impedance, and radiation patterns. The predicted results are compared with experimental results and excellent agreement is observed . These antenna elements are more suitable in applications where limited antenna real estate is available |
| URI: | http://dyuthi.cusat.ac.in/jspui/handle/dyuthi/1568 |
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| Analysis of a New Compact Microstrip Antenna.PDF | (3.188Mb) |
| Abstract: | A new compact micro strip antenna element is analyzed. The analysis can accurately predict the resonant frequency, input impedance, and radiation patterns. The predicted results are compared with experimental results and excellent agreement is observed . These antenna elements are more suitable in applications where limited antenna real estate is available |
| URI: | http://dyuthi.cusat.ac.in/purl/1362 |
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| Analysis of a New Compact Microstrip Antenna.PDF | (3.188Mb) |
| Abstract: | The closed form expression for the radiated power of a half-wave microstrip patch is modified to calculate the impedance bandwidth of a printed dipole. Analyses of cavity backed flared and end-loaded printed dipoles are presented |
| URI: | http://dyuthi.cusat.ac.in/jspui/handle/dyuthi/1578 |
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| Analysis of cavity backed printed dipoles.PDF | (989.1Kb) |
| Abstract: | Design equations are presented for calculating the resonance frequencies for a compact dual frequency arrow-shaped microstrip antenna. This provides a fast and simple way to predict the resonant frequencies of the antenna. The antenna is also analyzed using the IE3D simulation package. The theoretical predictions are found to be very close to the IE3D results and thus establish the validity of the design formulae |
| URI: | http://dyuthi.cusat.ac.in/purl/1381 |
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| Analytical Equa ... ncy Microstrip Antenna.PDF | (2.229Mb) |
| Abstract: | A modified H-plane sectoral horn antenna with identical E- and'H- plane.patterns over the X-band frequency is discussed. This system has significantly reduced side lobes and hack lobes. Half=power beam width and gain of the antenna are also improved with enhanced matching , Experimental results for a number of horns with various flanges are presented . These find practical application for illuminating symmetric antennas like paraboloids and polarization measurements in radio astronomy, etc. Compared to the fixed pyramidal horns. the present system offers great convenience in trimming the antenna characteristics |
| URI: | http://dyuthi.cusat.ac.in/purl/1433 |
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| Axially symmetr ... -plane sectoral horns.PDF | (1.253Mb) |
| Abstract: | A simple technique for obtaining identical E- and H-plane patterns from E-plane sectoral feed horn is presented. Halfpower beam width and gain of the antenna are also improved considerably. Experimental results for a number of horns with flanges of various parameters are also presented. This system may find practical application in radar and space communication systems |
| URI: | http://dyuthi.cusat.ac.in/purl/1431 |
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| Axially symmetr ... ne sectoral horn feeds.PDF | (1.818Mb) |
| Abstract: | Reduction of radar cross -section of dihedral corner reflectors using simulated corrugated surface (.SCS) is reported. This technique is found lo be more effective in the reduction of RCS or corner reflectors for normal incidence . A typical reduction of 40-50 dB is achieved using this method |
| URI: | http://dyuthi.cusat.ac.in/purl/1365 |
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| Backscattering ... rs using SCS technique.PDF | (1.362Mb) |
| Abstract: | Reduction of radar cross -section of dihedral corner reflectors using simulated corrugated surface (SCS) is reported. The technique is found to be more effective in the reduction of RCS or corner reflectors for normal incidence . A typical reduction of 40-50 dB is achieved using this method. |
| URI: | http://dyuthi.cusat.ac.in/jspui/handle/dyuthi/1575 |
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| Backscattering ... rs using SCS technique.PDF | (1.362Mb) |
| Abstract: | The impedance bandwidth of a high permittivity cylindrical dielectric resonator antenna excited by a micro strip line was significantly improved by modifying the feed geometry. The 10 dB return loss bandwidth is enhanced from 12 to 26% without much affecting the gain and other radiation properties of the antenna. Good agreement has been observed between the predicted and measured results |
| URI: | http://dyuthi.cusat.ac.in/purl/1359 |
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| Broadband cylin ... dified microstrip line.PDF | (1.018Mb) |
| Abstract: | The impedance bandwidth of a high permittivity cylindrical dielectric resonator antenna excited by a micro strip line was significantly improved by modifying the feed geometry. The 10 dB return loss bandwidth is enhanced from 12 to 26% without much affecting the gain and other radiation properties of the antenna. Good agreement has been observed between the predicted and measured results |
| URI: | http://dyuthi.cusat.ac.in/purl/1579 |
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| Broadband cylin ... dified microstrip line.PDF | (1.018Mb) |
| Abstract: | A new dual port microstrip antenna geometry for dual frequency operation is presented. The structure consists of the intersection of two circles of the same radius with their centres displaced by a small fraction of the wavelength . This antenna provides wide impedance bandwidth and excellent isolation between its ports. The gain of the antenna is comparable to that of a standard circular microstrip antenna operating at the same resonant frequency. A theoretical analysis for calculating the resonant frequencies of the two ports is also presented |
| URI: | http://dyuthi.cusat.ac.in/purl/1350 |
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| Broadband dual frequency microstrip antennas.PDF | (838.1Kb) |
| Broadband dual frequency microstrip antennas.PDF | (838.1Kb) |
| Abstract: | A microstrip antenna with large bandwidth is developed using a parasitic technique . Compared to the available wide-baud antennas,the proposed antenna structure is very compact and gives a lessdistorted radiation pattern with frequency . An impedance bandwidth,eight times that of a conventional patch antenna of the same size, Isachieved. The concept of coupled microstrip line model Is extended fortheoretical interpretation of the impedance loci |
| URI: | http://dyuthi.cusat.ac.in/purl/1360 |
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| Broad-Band Gap Coupled Microstrip Antenna.PDF | (2.586Mb) |
| Abstract: | A novel compact RFID tag employing open stubs in a microstrip transmission line is proposed. The prototype of the tag is fabricated on a substrate of dielectric constant 4.4 and loss tangent 0.0018. The tag consists of microstrip open stub resonators and cross polarized transmitting and receiving disc monopole antennas. A prototype of 8 bit data encoded tag is demonstrated in this communication. Method for enhancing the performance of the RFID tag is also proposed. Magnitude or group delay response can be used to decode the tag informations |
| Description: | Antennas and Propagation, IEEE Transactions on,VOL 60,issue 9,pp 4428-4432 |
| URI: | http://dyuthi.cusat.ac.in/purl/4323 |
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| Chipless RFID T ... p Open Stub Resonators.pdf | (980.4Kb) |
| URI: | http://dyuthi.cusat.ac.in/purl/1583 |
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| Circularly pola ... act microstrip antenna.PDF | (1.230Mb) |
Now showing items 1-20 of 145
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