time：2016/5/21 14:59:04 Views：
The antenna is a directional antenna, the antenna of the antenna is a kind of mobile communication system, which is mainly used for outdoor signal coverage. Whether it is GSM or CDMA, the plate antenna is the most common type of very important base station antenna. The antenna has the advantages of high gain, sector direction map, after small flap, vertical pattern depression control convenient, reliable sealing performance and long service life.
The antenna has different radiation or reception capacity in different directions, which is the direction of the antenna. According to the direction of the different, the antenna has two kinds of omnidirectional and directional. The following are mainly about the difference between them and related parameters.
Omnidirectional antenna: omnidirectional antennas, namely in the horizontal diagram performance of 360 degrees are uniform radiation, is usually said no direction, in the vertical direction chart performance for a certain width of the beam, the smaller lobe width at the general gain greater. Omnidirectional antenna in the communication system, the general application of the distance near, covering a large range, the price is cheap. Gain is generally below 9dB. Shown on the right map for omnidirectional antenna signal radiation. The radiation range of the omnidirectional antenna is more like an apple.
Directional antennas: also known as plate antenna. In the radiation range of a certain angle, that is usually said have direction in the horizontal diagram. In the vertical direction diagram performance for a certain width of the beam, with omnidirectional antennas, lobe width is small gain greater. The directional antenna is generally used in the communication system, and the communication distance is far, the coverage is small, the target density is big, the frequency utilization rate is high. There are directional antenna through the reflector board, but also through the array of synthesis (cost is too high, a special phased array antenna, a phase shifter with a thousand blocks, a T/R component about tens of thousands), the gain can reach 20dB.