The so-called signal shielding means that the receiving device cannot obtain a signal with a signal-to-noise ratio that meets the signal identification requirements. Signal to noise ratio (Signal Noise Ratio, SNR) is the most important content.

We can refer to the formula:

SNR = \frac{P_{Signal}}{P_{Noise}}

Therefore, there are two ideas for reducing the signal-to-noise ratio:

1. Reduce signal strength


2. Increase noise intensity

Based on the above ideas, we can use signal jammers to interfere/shield wireless signals.

The function of a signal jammer is to shield signals and is used in many situations. Nowadays, information spreads very fast. With a mobile device, all kinds of information can be spread to every corner in an instant. For some occasions where information cannot be spread, mobile phone signal cellphone jammer are very necessary.

Within a certain frequency range, mobile phones and base stations are connected through radio waves to complete data and sound transmission at a certain baud rate and modulation method;

Based on the above communication principle, the Dazhan jammer scans from the small-end frequency of the forward channel to the big-end at a certain speed during the working process. This scanning speed can cause garbled interference in the message signals received by the mobile phone. The mobile phone cannot detect normal data sent from the base station, making it impossible for the mobile phone to establish a connection with the base station. Communication equipment exhibits phenomena such as searching the network, no signal, and no service system.

Basic principles of 5G shielding:

Mobile phone signal jammers (jammers) achieve interference and shielding of wireless communication signals by emitting co-channel interference signals. The transmit power of the wifi signal jammer directly affects the strength of the interference signal, thereby indirectly affecting the shielding effect of the signal jammer. There is a positive correlation between these three. In other words, the stronger the transmission power, the stronger the interference signal, and the better the theoretical shielding effect in the same environment.

What factors affect the shielding effect? In the actual use environment, the interference signal emitted by the mobile phone signal jammer is affected by various factors, the most important of which are the following:

• The indoor jammer is recommended to be placed at a height of about 180cm-220cm above the ground, preferably at a forward angle.


• Is there any obstruction (such as walls, metal products, human body, etc.) between the gsm signal jammer and the wireless communication device (mobile phone, etc.). The interference signal emitted by the jammer will attenuate to varying degrees after passing through the obstruction, so please try to avoid it.


• The original wireless communication signal strength in the application environment of the jammer. The weaker the wireless communication signal strength in the use environment, the stronger the theoretical shielding effect of the jammer.


• The distance between the application environment of the jammer and the communication base station. The farther the application environment of the jammer is from the base station, the stronger the theoretical shielding effect of the jammer.