Grid Antennas

Wireless technology in industrial environments is becoming more and more common, whether it is utilizing Wi-Fi or proprietary systems for long-distance communication. In order for wireless technology to be successful, the signal must be transferred between a transmitter and receiver, converting the RF electrical signal from the transmitter into an electromagnetic wave in free space, and then converting that wave back again at the receiver. The device that makes this possible is the antenna. 

In industrial environments, there may be elements that interfere with the reception of a signal at the receiver and the right type of antenna can provide the transmission path to suit the application’s needs. Antennas come in many shapes and sizes and each has its own specific design characteristics that determine the range and radiation pattern of the radio signal. The radiation pattern or shape of the radio signal is what is referred to as antenna gain. Antenna gain is measured in decibels. The higher the gain of the antenna, the more focused the signal. The transmitting radiation pattern is the same as the sensitivity pattern for receiving. Which means that the direction in which the antenna transmits the strongest signal is also the direction in which it is most sensitive for receiving signals. 

Parabolic antennas have a parabolic reflector that has a high degree of directivity and the ability to focus radio frequency energy into a beam. They have a very narrow beam width, usually no greater than 25 degrees. Gain is dependent on diameter and frequency. A 1 meter antenna will provide about 26 dBi gain at 2.4 GHz, while a 10 meter antenna will provide 46 dBi gain at the same frequency. Parabolic antennas are used in long-range outdoor point-to-point connections.

Grid antennas are an alternative to a solid parabolic or dish antenna. Given that a solid parabolic reflector can be moved out of alignment due to heavy wind, the reflector in this case is perforated into a grid. The spacing of the grid elements is frequency dependent. Gain and beam width are similar to the parabolic antenna.