| 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) |
| URI: | http://dyuthi.cusat.ac.in/purl/1351 |
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| Dual frequency miniature microstrip antenna.PDF | (807.9Kb) |
| 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: | The effect of dopants with different valencies and ionic radii on the densification, structural ordering, and microwave dielectric properties of Ba(Mg1t3Tazt3)O3 (BMT) is investigated. It is found that dopants such as Sb,05, MnO, ZrO,, WO1, and ZnO improve the microwave dielectric properties of BMT. Addition of trivalent dopants is detrimental to the cation ordering and dielectric properties of BMT. A correlation between the microwave dielectric properties of BMT and ionic radii of the dopant has been established. The variation of the dielectric properties of pure and doped BMT at cryogenic temperatures is also discussed |
| URI: | http://dyuthi.cusat.ac.in/purl/1489 |
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| The effect of d ... o.33Ta0.67)03 ceramics.PDF | (5.114Mb) |
| URI: | http://dyuthi.cusat.ac.in/purl/1491 |
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| Effect of Nonst ... of Ba(Mgo.33Tao.67)03.PDF | (6.590Mb) |
| Abstract: | The effect of glass additives on the densification , phase evolution, microstructure and microwave dielectric properties of Ba(Mg1;3 Ta2i3)03 (BMT) was investigated . Different weight percentages of quenched glass such as B203 , Si02, B203-SiO2, ZnO-B203, 5ZnO-2B2O3, Al203-SiO2, Na20-2B203.10H20, BaO-B203-SiO2, MgO-B203-SiO2, PbO-B203-SiO2 , ZnO-B203-SiO2 and 2MgO-Al203-5SiO2 were added to calcined BMT precursor . The sintering temperature of the glass -added BMT samples were lowered down to 1300 °C compared to solid-state sintering where the temperature was 1650 °C. The formation of high temperature satellite phases such as Ba5Ta4O15 and Ba7Ta6O22 were found to be suppressed by the glass addition . Addition of glass systems such as B203, ZnO-B203, 5ZnO-2B203 and ZnO-B203-SiO2 improved the densification and microwave dielectric properties. Other glasses were found to react with BMT to form low-Q phases which prevented densification . The microwave dielectric properties of undoped BMT with a densification of 93 . 1 % of the theoretical density were Cr = 24 . 8, Tr = 8 ppm/°C and Q„ x f= 80,000 GHz. The BMT doped with 1.0 wt% of B203 has Q„ x f = 124,700GHz, Cr = 24.2, and T f = -1.3 ppm /°C. The unloaded Q factor of 0.2 wt% ZnO-B203-doped BMT was 136,500 GHz while that of 1.0 wt% of 5ZnO-2B203 added ceramic was Q„ x f= 141,800 GHz . The best microwave quality factor was observed for ZnO -B203-SiO2 (ZBS) glass-added ceramics which can act as a perfect liquid-phase medium for the sintering of BMT. The microwave dielectric properties of 0.2wt% ZBS-added BMT dielectric was Q„ x f= 152,800 GHz, F,= 25.5, and Tr = - 1.5 ppm/°C |
| URI: | http://dyuthi.cusat.ac.in/purl/1495 |
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| Effect of Nonst ... of Ba(Mgo.33Tao.67)03.PDF | (6.590Mb) |
| 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 novel technique fitr the bat dividth enhancement of conventional rectangular microstrip antenna is proposed in this paper. When a high permittivity dielectric resonator of suitable resonant frequency was loaded over the patch. the % bandwidth of the antenna was increased by more than five tunes without much affecting its gain and radiation performance. A much more improved bandwidth was obtained when the dielectric resonator was placed on the feedline. Experimental study shows a 2:1 VSWR bandwidth of more than 10% and excellent cross polarization performance with increased pass band and radiation coverage abnost the same as that of rectangular microstrip antenna |
| URI: | http://dyuthi.cusat.ac.in/purl/1389 |
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| Enhanced bandwi ... dielectric resonators.PDF | (1.874Mb) |
| Abstract: | Results of exhaustive study of the effect of metallic flanges on H-plane radiation characteristics of V-slot waveguide antenna are presented . It has been established that the beam can be sharpened or broadened by varying the flange angle . The adjustment of the flange angle and flange width would further improve the radiation pattern , yielding optimum efficiency from the flanged system |
| URI: | http://dyuthi.cusat.ac.in/purl/1436 |
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| An experimental ... slot waveguide antenna.PDF | (1.063Mb) |
| 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: | A novel compact chipless RFID tag using spurline resonators is discussed in this paper. The detection of the tag's ID is using the spectral signature of a spurline resonator circuit. The tag has a data capacity of 8-bits in the range 2.38 to 4.04 GHz. The tag consists of a spurline multiresonating circuit and two cross polarized antennas. The prototype of the tag is fabricated on a substrate CMET/ LK4.3 of dielectric constant 4.3 and loss tangent 0.0018. The measured results show that group delay response can also be used to decode the tag’s identity |
| Description: | RADIOENGINEERING, VOL. 23, APRIL 2014 |
| URI: | http://dyuthi.cusat.ac.in/purl/4338 |
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| Frequency Coded ... ng Spurline Resonators.pdf | (1.526Mb) |
| 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 new group of compounds with composition (Ba5-xSrx) Nb4015, having high permittivity and low loss have been prepared and characterized in the microwave frequency region . X-ray diffraction studies showed that monophase compound existed for all values of x from 0 to 5. Microwave dielectric properties such as and c f showed smooth variation with x , while the unloaded quality factor (Qu) showed remarkable improvement with x |
| URI: | http://dyuthi.cusat.ac.in/purl/1440 |
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| Sreemoolanadhan,H & Sebastian,M.T.PDF | (1.655Mb) |
| Abstract: | The paper presents a compact planar Ultra Wide Band ¯lter employing folded stepped impedance resonators with series capacitors and dumb bell shaped defected ground structures. An interdigital quarter wavelength coupled line is used for achieving the band pass characteristics. The transmission zeros are produced by stepped impedance resonators. The ¯lter has steep roll o® rate and good attenuation in its lower and upper stop bands, contributed by the series capacitor and defected ground structures respectively. |
| Description: | Progress In Electromagnetics Research C, Vol. 49, 123{131, 2014 |
| URI: | http://dyuthi.cusat.ac.in/purl/4340 |
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| High Selectivit ... Wide Band Applications.pdf | (423.9Kb) |
| 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: | In this paper, the advantages of using L-shaped microviij) feed to e.tcite a rectangular dielectric resonator cuuenna (DRA) by elemanagnetic coupling are presented. This feeding technique enhances the hardsvidth and gain of the antenna without affecting its size. The experimental re srdts are validated using Fidelity software based on the finitedifference tine-domain (FDTD) method |
| URI: | http://dyuthi.cusat.ac.in/purl/1425 |
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| L-strip-fed wid ... tric resonator antenna.PDF | (932.7Kb) |
| Abstract: | A novel antenna configuration comprised of two circular microstrip antennas (CMAs) resonating in the TMtt and TM2, modes, producing radiation characteristics suitable for a mobile telephone handset, is presented. The antennas operating at the same frequency are placed back to back with a separation comparable to the thickness of a typical handset. The radiation pattern consists of a region of reduced radiation intensity, which minimizes the radiation hazards to the user |
| Description: | Microwave and Optical Technology Letters,VOL 23,issue 6.pp 370-372 |
| URI: | http://dyuthi.cusat.ac.in/purl/4329 |
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| Microstrip Ante ... uced Radiation Hazards.PDF | (1.152Mb) |
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