Signal jamme internal antenna and external antenna
Signal jammers are widely used in examination rooms, prisons, detention centers and other places, which can effectively prevent personnel from using mobile phones in violation of regulations, ensure fairness and justice in examinations, and maintain prison order and safety. Signal jammers are divided into built-in radomes and external radomes. What is the difference between the two?
The only difference between an internal and external antenna is the mounting location. The internal antenna is built into the device. The external antenna can be mounted in a remote location.
The only reason to use an external antenna instead of an internal antenna is if the device being used will be mounted in a location where it cannot acquire the GPS signal. The internal antenna can receive the GPS signal through the windshield and even light, canvas top but not a hard or thick top.
Some devices have an internal high sensitivity GPS antenna built into them. These devices may pick up the GPS signal in locations where older internal antenna devices could not.
The best way to tell if an external antenna is needed is to place the device in the location where it will be mounted and power on the device. Allow the device ample time to acquire the GPS signal. If it can receive the signal in that location, an external antenna is not needed. If the device fails to acquire the GPS signal, an external antenna would be needed.
In terms of appearance and material, the built-in radome generally uses a plastic casing, while the external radome uses a metal casing.
In terms of usage, the biggest advantage of the built-in radome is that there is no need for additional wiring, and it is very convenient to use. You just need to plug it in and you can use it. In addition, because it is a built-in antenna, the antenna is less likely to be damaged by external impact.
The external antenna shield needs to be connected in the correct way, and the frequency of the antenna and the frequency of the fuselage must be screwed on accordingly. In addition, since the external antenna radome is made of metal and dissipates heat through the surface metal shell, the fuselage is relatively easy to get hot, which is also a normal phenomenon.
Among them, built-in radomes are also divided into built-in omnidirectional antennas and built-in directional antennas. Among them, the omnidirectional antenna is a 360-degree shield, and the directional antenna is an angled shield (120 degrees horizontally and 90 degrees vertically). The more cost-effective shields used in the examination room are basically built-in omnidirectional antennas, because they need to be shielded. Take down an entire classroom.
The effect of the mobile phone signal jammer gps is mainly determined by the power. If the equipment of the same power, the shielding effect of the external antenna and the built-in antenna is determined by The gain of the mounted antenna is determined by the antenna with high gain, and the output power of the antenna is higher, and the shielding effect is better.