time：2016-05-24 15:11:49 Views：
Omni-directional antenna, that is, in the horizontal direction of the picture is 360 degrees of uniform radiation, that is, the normal direction of the. Under normal circumstances the beam width is smaller, the greater the gain. 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.
The radiation range of the omnidirectional antenna is more like an apple.
Directional antenna, in the horizontal direction of the picture shows a certain angle range of radiation, which is usually said to have the direction of. The same as omni-directional antenna, beam width is smaller, the greater the gain. Directional antenna is generally used in communication system, which is in the environment of communication distance, small coverage, high target density and high frequency utilization.
We can also like this to think about the relationship between omnidirectional and directional antenna: omnidirectional antenna will send signals in all directions, front, back, left and right can receive the signal, directional antenna is like in the back of the antenna cover a bowl shaped reflector, signal only to the front transfer and shot into the back of the signal is reflector is blocked and reflection to the front, in front of the signal strength is strengthened. The signal radiation pattern of the directional antenna is shown below.