Monthly Archives: February 2008
The importance of Meta Tags
If your site doesn’t contain META tags, you aren’t ready to submit it to search engines! Most search engines use META tags as one component of their ranking formulas. The tags can increase your search engine rank and display important site information on the search results page.
Although only a few META tags directly relate to site promotion, you can use the others to provide valuable information about your Web page content. Continue reading →
WiFi Antenna properties
An antenna has three main properties: direction, gain and polarization.
Wireless Antenna Gain is term used for measuring of increase in signal power, as decibels (dB). Antenna with a higher gain is more effective in it’s radiation pattern.
Every antenna is designed to raise the power in the wanted direction and reduce it in unwanted directions. Gain of an antenna is reciprocal, meaning it is the same for transmitting and receiving.
Antenna Direction is the shape of the wireless signal after leaving the antenna.
Polarization of the wireless antenna is the orientation of the wireless signal.
It can be vertical, horizontal, circular or combinations of these.
The E-plane and H-plane are reference planes for linearly polarized antenna
This diagram showing the relationship between the E and H planes for a horizontally polarized directional antenna Continue reading →
WiFi Antenna types
Written by: http://www.wifi-antenna.com/
Parabolic grid & dish wireless antenna
This highly directional antenna type transmit/receives signals in a very narrow angle, so they are ideal for long distance and point to point network connections. It has a main reflector surface that is shaped like a paraboloid with an active element at its focus. That way reflector surface can reflect parallel signals to a single focal point. Parabolic wireless antenna are the best choice because very narrow beam-width will provide you withminimum interference with another wireless networks & longest signal distance & faster link
Yagi wireless antenna
A Yagi array wireless antenna is a semi-directional antenna commonly used in wireless communications. Yagi antenna is made from the array of dipoles (elements) parallel to each other exactly the same a s a standard TV rooftop antenna. The first (longest) element in this array is the reflector, second is the driven element and other elements are directors. The more directors the more gain. The are often house in cylinders to protect from the weather.
Omni directional Wifi antenna
This antenna sends and receives signals equally in all directions (360 degrees). Because of that property, this antenna type usually have the lowest gain and is used in point to multipoint links. An omni-directional antenna with an increased gain will increase distance, but decrease it’s effectiveness above and below the antenna, while low-gain type will do the opposite. Imaging the output of a standard supply 2dbi antenna the shape of a doughnut, its circular and fat, as the gain increases the doughnut is flattened out like a pancake to increase its range, this has the downside of losing signal off its low and high points. Again these antenna are housed in a fibre-glass tube to weatherproof.