Omnidirectional Radiation Performance Research Articles

Ultra‐wideband folded loop antenna fed by coplanar waveguide

AbstractIn this article, a novel and successful design of ultra‐wideband folded loop antenna is proposed and investigated. The antenna is fed by coplanar waveguide directly and can be fabricated easily by employing printed circuit board technology. It is studied both numerically and experimentally. From calculated and measured results, it may be observed that impedance bandwidth of over 130% for return loss lower than −9.54 dB and good omnidirectional radiation performance is obtained. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 3075–3077, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23890

Ultra-wideband CPW-fed antenna with round corner rectangular slot and partial circular patch

A novel coplanar waveguide (CPW)-fed ultra-wideband wide slot antenna is proposed. Because of the round corner of the rectangular slot and partial circular patch, the bandwidth of the antenna is enhanced largely. Good agreement between the measurement and simulation has been achieved. The results show that the impedance bandwidth of the antenna reaches up to 4.5–15.5 GHz for S11<−15 dB and 2.5–18 GHz for S11<−10 dB. Meanwhile, a good omni-directional radiation performance has also been achieved.

Compact frequency notched ultra-wideband fractal printed slot antenna

A novel frequency notched ultra-wideband (UWB) fractal printed slot antenna is proposed. The antenna is similar in configuration to a conventional microstrip-fed wide slot antenna, however, by introducing a Koch fractal slot, not only the size of the antenna is reduced significantly but also frequency notched function is achieved. Several properties of the antenna such as impedance bandwidth, frequency notched characteristics, radiation patterns and gain, have been investigated numerically and experimentally in detail. As will be seen, the operation bandwidth of the antenna is from 2.85 to 12GHz, in which a frequency notched band from 4.65 to 6.40GHz may be achieved, and relatively stable, omnidirectional radiation performance over the entire frequency range has also been obtained.

A New Nonuniform Meandered and Fork-Type Grounded Antenna for Triple-Band WLAN Applications

A new low-profile planar antenna with a nonuniform meander-line and a fork-type ground is proposed for triple-band wireless local-area network (WLAN) applications in IEEE 802.11b/g/a systems. The design for the antenna is simple and versatile since its radiation mechanism is clear and can be easily controlled. A prototype of the antenna has been constructed and demonstrates satisfactory performance. Measured and simulated return loss and radiation patterns have been obtained. Good impedance bandwidth and omni-directional radiation performance have been observed and demonstrate the promise for the WLAN applications

A balanced T-shaped antenna for 3G IMT2000 mobile handsets for WLAN

In this paper, a novel balanced T-shaped printed antenna is proposed for 3G IMT2000 mobile handsets for the WLAN (IEEE802.11b) module. This balanced T-shaped antenna is designed for microstrip-feeding with balanced signals. The antenna was designed by merging an unbalanced T-shaped antenna and a planar balun. A prototype of the antenna for operation at the IMT2000/IEEE802.11b bands is constructed and described. The measured and simulated return loss (in terms of the mixed-mode S-parameters) and measured radiation patterns are obtained. The experimental results demonstrate the broad bandwidth and omnidirectional radiation performance of the newly developed antenna. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 131–133, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21285

A compact internal double tailed-helical antenna (DTHA) for mobile handsets

In this paper, a novel internal antenna, called a double-tailed helical antenna (DTHA), is proposed for modern mobile handsets. A DTHA has the merits of being compact in size, cost effective, easy to manufacture, and easyto fine-tune, as well as having good electrical performance. A prototype of a DTHA for operation in the EGSM/DCS bands is constructed and shown. Its volume can be limited to 28 X 6 X 6.5 mm. The measured and simulated return losses and the measured radiation patterns are obtained. The experimental results demonstrate the broad bandwidth and omnidirectional radiation performance of the newly developed antenna.