A NOVEL DESIGN OF DUAL BAND MICROSTRIP ANTENNA FOR WIRELESS APPLICATIONS

A simple and compact inset fed dual band microstrip antenna is presented. The proposed antenna has a low profile and can easily be fed by using a 50 ohms microstripline. The proposed antenna covers all the 2.4/4.2 GHz WLAN/ RADIO ALTIMETERS operating bands, IEEE WLAN protocol 802.11 b/g employs 2.4 GHz. The antenna is simulated using An soft’s HFSSv11. Which shows good agreement with simulated results, Measured Return loss and Radiation patterns are observed to be nearly omnidirectional, moderate gain and wide frequcency band suitable for wireless applications. The antenna has an overall dimension of only 29.5mm x 38 mm x1.6mm, when printed on a FR4 substrate of dielectric constant 4.4

ULTRA WIDEBAND SLOTTED MODIFIED H-SHAPED MICROSTRIP PATCH ANTENNA FOR WIRELESS APPLICATIONS

The wireless communication system is gaining more and more progress in recent years with the support of microstrip patch antennas. Microstrip patch antennas are more comfortable for wireless devices due to their compactness, easy fabrication, and mounting. The ultra wideband slotted modified H-shaped microstrip patch antenna is presented in this article for wireless devices. Ultra wideband is achieved along with another small band makes it dual band pattern. The first band is a small band radiates at 2.95 GHz ranging from 2.68 GHz to 3.14 GHz with a bandwidth of 460 MHz. This is applicable in the wireless devices like WiMAX, IMT etc. The second band is the ultra wideband (UWB) radiates at 4.46 GHz, 8.2 GHz and 9.4 GHz ranging from 3.37 GHz to 10.1 GHz with a bandwidth of 6.73 GHz. WLAN, WiFi, WiMax and LTE can occupy this band to operate. Both the bands have maintained at VSWR<2 and the gain are kept at least -10 dB. The proposed antenna is simulated using High Frequency Structural Simulator (HFSS v15) software and fabricated on a low-cost FR4 substrate having a dielectric constant of 4.4 and height 1.6 mm with a 50-ohm microstrip line feeding. The miniaturization of the antenna is achieved with slots in the patch and ground plane, hence the name slotted patch and partial ground. The complete size of the antenna is 34x30x1.6 mm2. The simulated and experimental results are compared to conclude that both are lightly deviated

Concentration dependent optical and structural properties of Mo doped ZnTe thin films prepared by e-beam evaporation method

ZnTe doped with different concentrations of Molybdenum (Mo) thin films were prepared by e- beam evaporation method and the effect of doping on Optical and Structural properties of the thin films were studied. XRD results confirmed the doping of Mo through its signature peaks at 27.6 for MoTe2 (011) and 38.40 for Mo (220) along with the ZnTe (111) peak at 25.3. AFM images indicated the crystalline nature of ZnTe:Mo. The optical response observed through UV-VIS spectrometer revealed the transmittance was decreased from 50% (undoped) to 8% (doped with 25wt%). Similarly, the optical energy gap was also decreased from 2.27eV (undoped) to 1.7eV (doped with 25wt%). The results of the present study elucidate that ZnTe:Mo thin films can be considered as a good back contacts for photovoltaic (PV) applications, optical devices in general and CdTe based thin films solar cells in particular