The cell phone signal jammer sends the signal to the same frequency device. If the shielding device is turned on, when the mobile phone signal is disabled, the interference part will be successful. Nowadays, there are more and more mobile phone users, so mobile phone signal jammers are more civilian than electronic devices. It is prohibited to use mobile phone signals to interfere with specific locations.

The mobile phone signal jammer is an instrument used to protect mobile phones from receiving signals. The mobile phone signal jammer plays signals with the same frequency to the GSM modem. If the mobile phone signal jammer is disabled, the interference will be successful.

Cellular phones are full-duplex devices that can use two frequencies at the same time, one for speaking and one for listening, and process the signals simultaneously. If there is signal blocking, only one frequency can be blocked at a time. Because mobile phones can only access one of the frequencies, both frequencies are blocked because they think there is no service in this area.

The principle of disrupting cell phones is similar to how 3G interferes with other types of radio communications. In order to use a cell phone, signals are sent from the cell phone to the cell phone tower. There are several cell towers in a city, and cell phone users move from one tower to another as they move through an area.

A signal blocker emits the same radio frequency as a cell phone, interrupting communications between the cell phone and the base station in the tower by denying radio signals to users in the area covered by the jamming device, also known as a denial-of-service attack.

There are different types of mobile phone signal shielding currently on the market. Some devices can only block a single frequency, while others can block all types of networks at the same time. The latter can automatically switch to a model that looks for open signals from different networks. High-end devices can block at the same time. Full frequency, other devices can be adjusted to specific frequencies.

Simply put, they emit random static or noise over a wide frequency range that is so powerful that approaching devices cannot connect where it is supposed to. It's a bit like being next to the engine of a sports car, opening the hood, and trying to talk to someone on the phone. The localized noise becomes so strong that the device cannot make regular connections. They effectively prevent equipment from functioning properly to quickly cover a range of frequencies.

The carrier frequency of the electromagnetic interference signal is the same as the carrier frequency, so the receiver and amplifier solve (subtract) the interference signal and the interference signal at the receiving end at the same time.