Tag Archive How much do you know about the gain performance of the antenna

Gain means that when the input power is equal, the letter generated by the actual antenna and the ideal radiation unit at the same point in space.
The ratio of the power density to the number. It quantitatively describes the degree of concentration of an input power by an antenna. The gain is obviously related to the antenna pattern. The narrower the main lobe, the smaller the sidelobe and the higher the gain. It is possible to understand the physical meaning of gain by generating signals of a certain size at certain points at a certain distance.
Antenna gain is used to measure the ability of antennas to transmit and receive signals in a specific direction. It is one of the most important parameters for selecting base station antennas.
Generally speaking, gain enhancement mainly depends on reducing the width of the vertical radiating lobe, and maintaining the omnidirectional radiation performance on the horizontal plane. Antenna gain is very important for the operation quality of mobile communication system, because it determines the signal level of the cellular edge.  Increasing the gain can increase the coverage of the network in a definite direction, or increase the gain margin within a certain range.  Any cellular system is a two-way process, increasing the gain of the antenna and reducing the gain Budget Margin of the bidirectional system. In addition, the parameters for antenna gain are dBd and dBi.  The DBi is relative to the gain of the point source antenna, and the radiation in all directions is uniform; the gain of dBd relative to the symmetrical phase antenna is dBi=dBd+2.15. Under the same conditions, the higher the gain, the farther the distance is. Generally, the antenna gain of GSM directional base station is 18dBi and omnidirectional 11dBi.
If an ideal non directional point source is used as the transmitting antenna, the input power of 100W is required, and when a directional antenna with a gain of G = 13 dB = 20 is a transmitting antenna, the input power is only 100 / 20 = 5W. In other words, the gain of an antenna, with the radiating effect on its maximum radiation direction, and the direction free theory. Compare the input power magnification with the point source.
The gain of the half wave symmetric oscillator is G = 2.15 dBi; the 4.5 wave symmetric oscillator is arranged along the vertical line, forming a vertical.
The gain of the four element array is about G = 8.15 dBi (dBi this unit represents the ideal source of the homogeneous radiation.
If the half wave symmetric oscillator is used as a comparison object, the unit of gain is dBd.