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Search Results: 1 - 10 of 23028 matches for " Jamshed Aslam Ansari;Nagendra Prasad Yadav;Prabhakar Singh;Anurag Mishra "
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Compact Half U-Slot Loaded Shorted Rectangular Patch Antenna for Broadband Operation
Jamshed Aslam Ansari;Nagendra Prasad Yadav;Prabhakar Singh;Anurag Mishra
PIER M , 2009, DOI: 10.2528/PIERM09090102
Abstract: In this paper, analysis of half U-slot loaded patch antenna with shorting wall is presented. The parameters of the antenna significantly depend on slot and notch dimensions. Bandwidth of the proposed antenna is found to be 21.59%. The 3dB beamwidth of the antenna is found to be 90 at the central frequency of 2.6 GHz. The theoretical results are compared with IE3D simulated and experimental ones which are in good agreement.
Compact Shorted Microstrip Patch Antenna for Dual Band Operation
Anurag Mishra;Prabhakar Singh;Nagendra Prasad Yadav;Jamshed Aslam Ansari;Babau Ram Vishvakarma
PIER C , 2009, DOI: 10.2528/PIERC09071007
Abstract: In the present paper notch loaded shorted microstrip patch antenna has been analysed using cavity model. The proposed antenna shows dual band operation which depends on notch dimensions as well as shorting wall. The frequency ratio is found to be 1.5278 for the notch loaded rectangular patch, while in notch loaded shorted patch, the frequency ratio varies from 2.9764 to 2.725 for increasing value of notch width and it is almost invariant with notch depth. Further a slot loaded shorted patch antenna shows the dual frequency nature with the frequency ratio1.7. The theoretical results are compared with IE3D simulation as well as reported experimental results.
Analysis of Shorting Pin Loaded Half Disk Patch Antenna for Wideband Operation
Jamshed Aslam Ansari;Prabhakar Singh;Nagendra Prasad Yadav;Babau Ram Vishvakarma
PIER C , 2009, DOI: 10.2528/PIERC09011203
Abstract: In the present paper the analysis of notch loaded shorted half disk patch is given. It is found that the bandwidth of the antenna depends inversely on the notch width whereas it is invariant with the notch length. Further antenna shows dual band behavior for a gap spacing below 7.5 mm in the gap coupled half disk shorted patch whereas it behaves as a wideband antenna for gap spacing more than 7.5 mm. Theoretical results are compared with simulated and experimental results.
Half U-Slot Loaded Semicircular Disk Patch Antenna for GSM Mobile Phone and Optical Communications
Jamshed Aslam Ansari;Anurag Mishra;Babau Ram Vishvakarma
PIER C , 2011, DOI: 10.2528/PIERC10100704
Abstract: In the present paper a dual frequency resonance antenna is achieved by introducing half U-shaped slot in semicircular disk. It is analysed by using circuit theory concept. The resonance frequency is found to be 1.50 GHz and 2.32 GHz, and the bandwidth of the proposed antenna for lower and upper resonance frequency is found to be 5.96% and 11.08% respectively. It is found that the resonance frequency depends inversely on the slot length and feed point, while it increases with increasing the slot width and coaxial probe feed radius. The frequency ratio is found to be 1.54. The theoretical results are compared with IE3D simulation as well as reported experimental results, and they are in good agreement.
Analysis of a Gap-Coupled Stacked Annular Ring Microstrip Antenna
Jamshed Aslam Ansari;Ram Brij Ram;Prabhakar Singh
PIER B , 2008, DOI: 10.2528/PIERB08011103
Abstract: A theoretical analysis of a gap-coupled stacked annular ringmicrostrip antenna with superstrate is performed in order to obtain wider bandwidth operation. The effects of air gap, superstrate thickness and feedingp oint location on the antenna performance are analyzed in TM mode usingequiv alent circuit concept. It is noted that the proposed antenna is very sensitive to the feedingp oint location in TM mode while annular ringmicrostrip patch antenna is independent of feed point in that mode. The optimized proposed antenna shows an impedance bandwidth of 13.96% whereas the antenna without air-gap has 8.75% bandwidth and without superstrate it has bandwidth of 10.89%. The theoretical results are compared with simulated and experimental results.
H- Shaped Stacked Patch Antenna for Dual Band Operation
Jamshed Aslam Ansari;Prabhakar Singh;Satya Kesh Dubey;Rahmat Ullah Khan;Babau Ram Vishvakarma
PIER B , 2008, DOI: 10.2528/PIERB08031203
Abstract: Analysis of U-slot loaded patch stacked with H-shaped parasitic elements is given in this paper. It is found that the antenna exhibits dual resonance and both the resonance frequency (upper and lower) depends directly on slot width and inversely on slot length. Both upper and lower resonance frequency increase with increasing the value of . Typically the bandwidth at lower and upper resonance is found 3.66% and 10.25% respectively. The radiated power at higher frequency (beamwidth 64) is 0.73 dB as compared to lower resonance frequency (beamwidth 71). The theoretical results are compared with the simulated data obtained from IE3D.
Double U-Shaped Slots Loaded Stacked Patch Antenna for Multiband Operation  [PDF]
Nagendra Prasad Yadav
Open Journal of Antennas and Propagation (OJAPr) , 2015, DOI: 10.4236/ojapr.2015.32002
Abstract: The design of a seven-band stacked patch antenna for the C, X and Ku band is presented. The antenna consists of an H-slot loaded fed patch, stacked with dual U-slot loaded rectangular patch to generate the seven frequency bands. The total size of the antenna is 39.25 × 29.25 mm2. The multiband stacked patch antenna is studied and designed using IE3D simulator. For verification of simulation results, the antenna is analyzed by circuit theory concept. The simulated return loss, radiation pattern and gain are presented. Simulated results show that the antenna can be designed to cover the frequency bands from (4.24 GHz to 4.50 GHz, 5.02 GHz to 5.25 GHz) in C-band application, (7.84 GHz to 8.23 GHz) in X-band and (12.16 GHz to 12.35 GHz, 14.25 GHz to 14.76 GHz, 15.25 GHz to 15.51 GHz, 17.52 GHz to 17.86 GHz) in Ku band applications. The bandwidths of each band of the proposed antenna are 5.9%, 4.5%, 4.83%, 2.36%, 3.53%, 1.68% and 1.91%. Similarly the gains of the proposed band are 2.80 dBi, 4.39 dBi, 4.54 dBi, 10.26 dBi, 8.36 dBi and 9.91 dBi, respectively.
Cryptosporidium infection in school children in Dhanusha district, Nepal
Nagendra Prasad Yadav,DK Sah,S Manadhar,JK Singh
Janaki Medical College Journal of Medical Science , 2013, DOI: 10.3126/jmcjms.v1i2.9268
Abstract: Background and Objectives: Gastro-intestinal water-borne infections are among the most emerging and re-emerging infectious diseases throughout the world. Most water-borne diseases are caused by organism ranging from microscopic viruses of less than 30 nm in diameter to parasites of 10cm in length culminate into diarrhea and cause approximately 5million reported deaths annually. The purpose of the present study was to evaluate the prevalence of intestinal parasites, Cryptosporidium parvum among school children.
Crystallization Kinematics and Dielectric Behavior of (Ba,Sr)TiO3 Borosilicate Glass Ceramics  [PDF]
Avadhesh Kumar Yadav, Chandkiram Gautam, Prabhakar Singh
New Journal of Glass and Ceramics (NJGC) , 2012, DOI: 10.4236/njgc.2012.23018
Abstract: Perovskite [(Ba0.6Sr0.4)TiO3]-[2SiO2-B2O3]-[K2O]-La2O3 glass was prepared by conventional melt quench method. The differential thermal analysis (DTA) was performed on glass sample in the temperature range from 100℃ to 1000℃ by different heating rate to study the crystallization kinematics. The kinetic parameters characterizing the crystallization have been determined using an Arrhenius model. Glass samples were subjected to appropriate heat treatment schedules for their suitable crystallization. X-ray diffraction analysis (XRD) of glass and glass ceramic samples were done to check the amorphous state and crystalline nature. XRD of glass ceramic sample shows the major perovskite phase of BaTiO3 (BT) along with the formation of secondary phases Ba2TiSi2O8 (BTS) and Ba2Ti2B2O9 (BTB). Scanning electron microscopy (SEM) is also studied to see the morphology of the grains of major and secondary phase formation in BST glass ceramic samples. La2O3 is played an important role to increase the nucleation of the crystallites in the glassy matrix. The addition of La22O3 results in development of well interconnected crystallites formed as major phase of BST. In this paper, we are reporting the crystallization behavior of BST borosilicate glass system and high temperature dielectric characteristics of their glass ceramics.
E-Shaped Patch Symmetrically Loaded with Tunnel Diodes for Frequency Agile/Broadband Operation
Jamshed Aslam Ansari;Ram Brij Ram
PIER B , 2008, DOI: 10.2528/PIERB07101202
Abstract: Analysis of a frequency agile broadband E-shaped patch antenna (ESPA) symmetrically loaded with tunnel diodes is presented in this paper. The notch parameters such as notch-length, notch-width and position are optimized to achieve the optimum broadband operation of ESPA. Under the optimum conditions of ESPA (bandwidth 32.35%), the performance of the antenna is also analyzed as a function of bias voltage of tunnel diode. It may be mentioned that the proposed antenna can be operated in tunable band that varies from 1055 MHz (bandwidth 42.54%) to 1324 MHz (bandwidth 49.77%) with the bias voltage. Further, the radiated power of the proposed antenna is enhanced by 5.67 dB as compared to the E-shaped patch antenna.
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