The vehicle antenna refers to a mobile communication antenna designed to be mounted on a vehicle, and the common one is a suction cup antenna. Since the suction cup antenna is easy to install, it is often used in some simple installations to replace the base station antenna with a suction cup antenna.
The vehicle antenna structure has antennas in the form of shortened, quarter-wavelength, central plus-sensing, five-eighth wavelength, and double-half wavelength. In theory, their efficiency increases sequentially, and the antenna of the same working frequency band The length also increases in turn. Due to the limited height of the vehicle itself and the wind resistance formed by the long antenna when the vehicle is moving at a high speed, crossing the bridge hole and entering the underground garage are problems. Therefore, the vehicle antenna is not as long as possible, and the car antenna is generally required to be no more than 70 cm. The van requires a shorter antenna. The shortened antenna is small in size, although the gain is not high, but it is suitable for applications where a hidden antenna is required.
General police vehicles are recommended to install high-enhancement antennas, especially in vehicles with a large range of active areas. The 350MHZ high-gain antenna is divided into five-eighth wavelength plus sense, at a distance of one-half wavelength from the top of the antenna. A plus inductance coil. The double-half-wavelength antenna of the 400 MHz band has a higher gain, and its appearance is characterized by two sensible coils on the antenna of the antenna. The five-eighth wavelength antenna and the central-sensing antenna also have higher gains and are relatively inexpensive, so they are widely used.
In the case of being used as a temporary fixed station antenna, it is conceivable to select a suction cup antenna with a high gain, and the length of the antenna does not have to be excessively limited. Since the suction cup antenna is designed according to the environment in which the automobile is used, it is better to use a metal plate (such as a metal sheet) having a radius of more than 1 m under the fixed use. Since the imported original car antenna is very expensive and the advantages are not outstanding, the domestic car antenna is generally used. In the antenna selection stage, the antenna's appearance and gain are mainly referred to. It is recommended to use the famous car antenna brand, the parameters they provide are more authentic and the manufacturing process is guaranteed. If it is a bulk purchase, it can be customized to the antenna manufacturer according to the frequency band used for better use.