1.Why the antenna of network mobile radio is not external?
Re: Because the antenna will lose signal in the process of transmitting.
The longer the length of the antenna, the greater the loss.
In order to reduce the signal lose,and the engineer use the best feeder line.
They reduce the antenna length to 1 meter for testing,and turns out the internal antenna has better signal than external antenna.
Also test 1.5~2.5m.the result is the same.the internal antenna has the better signal.
2. Why do traditional platforms use external antennas?
Re: Because the traditional mobile radio use low frequency 400Mhz,the antenna signal lose is very small.
The network mobile radio is high frequency 2000mhz,the antenna lose is large
3. The main antenna mainly depends on the area of the antenna. The size of the radio is large, so the antenna area can be 4-5 times of the cell phone antenna, and the effect will be better than the external antenna.And the cell phone is also a built-in antenna that can be used well.
4. Why it can be external of the GPS antenna ?But the network antenna is not recommended external?
Re:Because the GPS antenna has power, it can be took the power signal, but the network antenna has no power, it can only take the frequency and loss is large.