Visualizing Magnitude and Direction in Flow Fields

In weather visualizations, it is common to see vector data represented by glyphs placed on grids. The glyphs either do not encode magnitude in readable steps, or have designs that interfere with the data. The grids form strong but irrelevant patterns. Directional, quantitative glyphs bent along streamlines are more effective for visualizing flow patterns. With the goal of improving the perception of flow patterns in weather forecasts, we designed and evaluated two variations on a glyph commonly used to encode wind speed and direction in weather visualizations. We tested the ability of subjects to determine wind direction and speed: the results show the new designs are superior to the traditional. In a second study we designed and evaluated new methods for representing modeled wave data using similar streamline-based designs. We asked subjects to rate the marine weather visualizations: the results revealed a preference for some of the new designs

Planar Inverted-F Antennas (PIFA) for multiband wireless applications

This is a post-print version of the article - Copyright @ 2010 IEEEA compact reconfigurable four bands Planar Inverted-F Antenna (PIFA) is presented for Digital Video Broadcasting – Handheld (DVB-H), Universal Mobile Telecommunications System (UMTS), Global System for Mobile Communications (GSM800, 900, 1800 and 1900), Personal Communications System (PCS), Wireless Local Area Network and Bluetooth (WLAN), Worldwide Interoperability for Microwave Access (m-WiMAX) and Hiperlan/2 applications. Two varactor diodes with variable capacitors are used to electrically tune the operating frequencies over a wide range. The overall size of the radiated parts is 31.5 x 30.5 mm2 which makes it easy to integrate it into small mobile handset. Depending on the voltage applied to the switches the operating frequencies at 0.7 GHz, 2 GHz, 3.5 GHz and 5 GHz can be tuned over 30.48%, 20%, 4% and 4% respectively. The peak gains for the four bands range -4dBi, 3dBi, 3dBi and 6dBi at DVB-H, UMTS, WiAMX and WLAN, respectively. The average efficiency of the four bands ranges from 95% to 85%. The radiation patterns and other discussions are provide

Ground independent planar inverted-F antenna (PIFA) for very small mobile phone

Copyright @ 2010 LAPCA small ultr-thin tri-band Planar Inverted-F Antenna (PIFA) is presented. The proposed antenna consists of slotted radiated parts supported by shorting walls and a ground plane. Intensive investigations are carried out in this paper to show that the ground plane and the antenna locations have insignificant effect on the performance of the antenna while the physical height of the radiated parts can be more significant. The radiated parts occupied a total size of 26 x 25.6 x 3.57 mm3. It designed to operate at UMTS, m-WiMAX and 5 GHz WLAN bands. Simulated and measured results are in good agreements

PIFA based reconfigurable multiband antenna for wireless applications

Copyright @ 2010 IEEEA compact reconfigurable four bands Planar Inverted-F Antenna (PIFA) is presented for Digital Video Broadcasting - Handheld (DVB-H), Universal Mobile Telecommunications System (UMTS), Global System for Mobile Communications (GSM800, 900, 1800 and 1900), Personal Communications System (PCS), Wireless Local Area Network and Bluetooth (WLAN), Worldwide Interoperability for Microwave Access (m-WiMAX) and Hiperlan/2 applications. Two varactor diodes with variable capacitors are used to electrically tune the operating frequencies over a wide range. The overall size of the radiated parts is 31.5 × 30.5 mm2 which makes it easy to integrate it into small mobile handset. Depending on the voltage applied to the switches the operating frequencies at 0.7 GHz, 2 GHz, 3.5 GHz and 5 GHz can be tuned over 30.48%, 20%, 4% and 4% respectively. The peak gains for the four bands range -4dBi, 3dBi, 3dBi and 6dBi at DVB-H, UMTS, WiAMX and WLAN, respectively. The average efficiency of the four bands ranges from 95% to 85%. The radiation patterns and other discussions are provided

Compact wideband patch antenna for 5 and 6 GHz WLAN applications

Copyright @ 2008 IEICEA wideband rectangular and circular mistostrip patch antenna for 5 and 6 GHz WLAN applications is presented. The rectangular and the circular patches are fed by microstrip line. All the structure is placed on the same layer with a very simple structure. The impedance bandwidth for the antenna presented 22.41 % ranging from 5.15 GHz to 6.45 GHz. The radiation pattern including E-plane and H-plane is satisfactory within this bandwidth

Triple band double U-slots patch antenna for WiMAX mobile applications

A small triple-band 2.7 GHz, 3.2 GHz and 5.3 GHz compact microstrip patch antenna with two U-shaped slots and a small ground plane is presented. It has been developed to be used in future WiMAX technology. The required bandwidths are fulfilled the WiMAX technology 4.8 %, 3 % and 2.5 % respectively. The return loss for the triple band are -18.5 dB, -14.5 dB and -19 respectively

Multi-band antenna for different wireless applications

A small multi-band compact antenna is presented. The antenna is designed on Roger RT/duroid 5880 with dielectric constant 2.2, multi-band operations is achieved by inserting a slot on the top patch. The antenna has wide impedance bandwidth at 1.2, 1.6, 2.4 and 2.6 GHz with Gain 4.2, 1, 5 and 2 dBi respectively. The bandwidth before adding the shorting wall and the slot was 3.72%, whereas after adding the shorting wall and the slot the bandwidth get wider to 31.9% at the centre of 1.4 GHz. The radiation pattern has acceptable response with low cross polarization at both E-plane and H-plane. The overall dimension of the ground plane is 70 X 70 X 1.5 m

Bandwidth enhancement for small patch antenna using PBG structure for different wireless applications

A design strategy using Photonic Band Gap (PBG) structure on ground plane to achieve wider bandwidth for patch antenna is presented. It is found that, the impedance bandwidth has improved from 3.72% to 31.9% at centre frequency 9 GHz after adding PBG on the ground plane. The antenna has multi band operations at 5, 6 and 9 GHz. E-Plane and H-plane radiation patter is satisfied within this band

Bandwidth enhancement for patch antenna using PBG slot structure for 5, 6 and 9 GHz applications

A design strategy using photonic band gap (PBG) structure on ground plane to achieve wider bandwidth for patch antenna is presented. It is found that, the impedance bandwidth has improved from 3.72% to 31.9% at centre frequency 9 GHz after adding PBG on the ground plane. The antenna has multi band operations at 5, 6 and 9 GHz. E-Plane and H-plane radiation patter is satisfied within this bands

Bandwidth enhancement for microstrip patch antenna using stacked patch and slot

Small size wideband microstrip patch antenna with slot in ground plane and stacked patch fed through microstrip line is presented. By inserting slot on ground plane and stacked patch supported by wall, the bandwidth can improve up to 25% without significant change in the frequency. The bandwidth before adding the slot and the stacked patch was 3.72%, whereas after adding the slot and the stacked patch the bandwidth increased up to 25% ranging from 2.45 to 3.3 GHz. The radiation pattern has acceptable response at both E-plane and H-plane. The ground plane size is 30 mm by 90 mm, the antenna designed is based on Roger RT/duroid 5880 with dielectric constant 2.