1,721,063 research outputs found
Active integrated antenna using T-shaped microstrip-line-fed slot antenna
No full textAn active integrated antenna (AIA) which consists of a T-shaped microstrip-line-fed slot antenna is proposed. Since the designed antenna has an electromagnetically coupled feedback loop, it can easily solve the problem of DC isolation between a radiator and amplifier. The fabricated parallel-feedback antenna oscillator shows stable oscillation at a frequency of 10.05 GHz. The measured effective isotropic radiated power (EIRP) is 37.79 m W, and the cross-polarization levels are at least -15-dB lower than those of co-polarization for all directions. (c) 2005 Wiley Periodicals, Inc
Internal antenna with modified monopole type for DVB-H applications
No full textAn internal modified monopole antenna for DVB-H band is presented. By extending the feeding line of the modified monopole and locating it over a ground plane, a wideband input impedance of 328 MHz within 6:1 VSWR is achieved. The proposed antenna has an approximately omnidirectional radiation pattern and yields greater than -3 dBi antenna gain covering DVB-H band. These features are suitable for DVB-H applications
A novel compact and wideband shorted patch antenna
No full textA novel compact shorted patch antenna with the bowtie-type patch and the dual triangle portion to obtain a large bandwidth (790-970 MHz) is presented in this paper. Using shorted patches with via holes, a size reduction of 95.7% is achieved, as compared to that of the conventional half-wave patch antenna. Moreover. it has 10-dB return-loss bandwidth of 20.4% for the GSM and CDMA bands. This proposed antenna exhibits not only a compact and a thin profile. bill also wideband characteristics. (c) 2005 Wiley Periodicals. Inc
SWNT patterning on solid surfaces using photolithography & micro-contact printing method
No full textLow-threshold blue amplified spontaneous emission in a statistical copolymer and its blend
No full textWe report low-threshold, blue amplified spontaneous emission (ASE) in a statistical copolymer, poly(9,9-dihexylfluorene-2,7-divinylene-m-phenylenevinylene-stat-p-phenylenevinylene) (CPDHFPV) and its blend with poly(9-vinylcarbazole) (PVK). PVK and CPDHFPV acted as the donor and the acceptor of the Forster-type excitation energy transfer, respectively. A single component waveguide made of CPDHFPV gave the threshold energy of 160 nJ/cm(2)/pulse. Moreover, that of the PVK/CPDHFPV (95/5 by wt.) blend device was as low as 20 nJ/cm(2)/pulse. From the relationship between the ASE intensity and the film thickness, we suggest that the optimum thickness for the photopumped ASE should be the transverse electric-mode cutoff thickness. (C) 2002 American Institute of Physics
A miniature UWB planar monopole antenna with 5-GHz band-rejection filter and the time-domain characteristics
No full textA planar monopole antenna with a staircase shape and small volume (25 x 26 x 1 mm(3)) is proposed in this paper. With the use of a half-bowtie radiating element, the staircase-shape, and a modified ground plane structure, the proposed antenna has a very wide impedance bandwidth measured at about 11.6 GHz (2.9-14.5 GHz, bandwidth ratio about 1:5) below VSWR 2 including the WLAN band notched in the vicinity of 5 GHz. An omnidirectional radiation pattern is obtained. The group delay which is an indication of linearity between two proposed antennas is less than 1 ns. The electrical characteristics in terms of frequency and time domains and physical ones of the proposed antenna make it attractive for use in ultrawideband (UWB) systems
Patterning and aligning of SWNTs on solid substrates using micro-contact printing method
No full textElectrostatic Energy Harvaster for Low-Frequency Vibration by Human Physical Motions using Luquid
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