vehicle antenna for receiving radio signals and strengthen the current multi-signal is weak in most parts of our country, car needs an external antenna, the signal is very helpful in unstable regions. Electrostatic discharge is a car antenna, the main car is traveling out of the housing accumulation of electrostatic discharge, and automotive occupant safety protection circuit member refers in radio device for transmitting or receiving electromagnetic waves. Any use of electromagnetic waves to transmit information, such as radio communication, radio, television, radar and other engineering systems, are required to work the antenna. The antenna according to applications can be divided into handheld station antenna, car antenna, antenna base three categories. It refers to mobile communications antenna designed to be mounted on the vehicle, the most common is the sucker antenna. Because sucker antenna installation place easily, so in some places is often easy to establish the station instead of the base antenna sucker antenna.
1. antenna function Category
(a) by type
1, car TV antenna
2, car radio antenna
3, GPS vehicle antenna
4. Anti-static antenna
5, automotive automatic retractable antenna
(b) the installation type
1, Adhesive [123 ]
2, sucker
3, plug-type
4, the thread
5, the suction roof
6, a glass paste [ 123]
7, the card edge formula
2. the antenna structure
has shortened the vehicle antenna structure, a quarter wavelength, plus central sensitized, five eighths wavelength one form of double-half wavelength antenna and the like, successively increase their efficiency theoretically, the same length of the antenna operating band is also sequentially increased.
1. shortened.
because the vehicle itself is limited, coupled with long antenna drag formed when the vehicle travels at high speed, over the bridge opening, into the underground garage are the problem, so the car antenna is not as long as possible, generally require car antenna is not more than 70 cm, van class requires a shorter antenna. Shortening the antenna compact, although the gain is not high, but suitable for use in situations where covert antenna.
2. The five-eighths of the wavelength and the central plus sensitized.
police vehicles generally recommended to install a high gain antenna, especially in the relatively large range of the active area of the vehicle, 350MHZ high gain antenna is divided into multiple plus five-eighths of a wavelength in the sense of form, the top half away from the antenna at one of the wavelengths from a loading coil. 400MHZ dual band half-wave antenna having higher gain, its appearance characterized by a loading coil on the two dipole antenna.
five eighths wavelength and central plus sensitized also have high gain, and the price is relatively cheap, so is widely used. In the case of use as a temporary fixed station antenna may be considered optional sucker high gain antenna length of the antenna do not have too many restrictions. The automobile antenna suction cup is designed so that in use environment when used as a fixed suction plate a radius greater than 1 m (e.g., metal) would be better used since the effect thereof.
Since the original imported car antenna is very expensive and the advantage is not prominent, so generally use domestic car antenna. In the main antenna selection phase reference antenna gain and appearance. It suggested the use of large manufacturers of brand-name, parameter authenticity they provide relatively high, the manufacturing process is also guaranteed. If it is entirely possible to bulk purchases of professional antenna manufacturer customized by using the band to get the best results.