Problems related to signal jammers are very common. Understanding their working principle, shielding range and legal regulations can help us correctly recognize this type of equipment. The core working principle is to emit extremely strong interference noise in a specific frequency band. This noise will "drown out" normal communication signals, causing mobile phones, routers and other devices to be unable to establish stable connections with base stations or signal sources, thereby achieving a signal shielding effect.
Which signals a signal jammer can block is entirely determined by its design objective and power size. Specifically, it can be divided into the following two categories:
First, common signals to be shielded (Main targets of civilian-grade jammers
The design intention of civilian-grade jammers is mostly aimed at public communication and wireless networks that are frequently used in daily life, mainly including the following types of signals:
1.Public mobile networks (2G, 3G, 4G, 5G)
This is the most core shielding object of the jammer, which can cover all the commonly used communication frequency bands of mobile phones. After blocking, the mobile phone will display a status of "No Service" or "Emergency Calls only", unable to make calls, send text messages, or use mobile data to access the Internet. As different communication standards (such as GSM, CDMA, WCDMA, LTE, NR) correspond to different frequency bands, a full-band civilian jammer will cover all frequency bands of these standards to ensure complete blocking of mobile phone signals.
2. Wi-Fi signal (2.4GHz, 5GHz, 6GHz)
The jammer will interfere with all the commonly used Wi-Fi frequency bands. No matter which frequency band of Wi-Fi router the device attempts to connect to, it will fail to connect successfully due to signal interference, eventually leading to the interruption of the wireless network and the inability to perform network operations such as web browsing and file transfer.
3. Bluetooth signal (2.4GHz)
Bluetooth devices (such as Bluetooth headphones, Bluetooth keyboards, Bluetooth mice, Bluetooth speakers, etc.) all communicate using the 2.4GHz frequency band. Interference from a jammer on this frequency band will directly interrupt all Bluetooth connections, preventing normal pairing between devices and data transmission.
4. Satellite positioning signals (GPS, Beidou, Glonass)
This type of signal shielding mainly targets the positioning function of devices. After interference, devices that rely on satellite positioning, such as mobile phones, car navigation systems, and drones, will be unable to obtain accurate location information and thus unable to achieve functions such as navigation and positioning tracking. It should be particularly noted that interfering with satellite positioning signals such as GPS is a serious illegal act in most countries and regions around the world. Do not attempt it.
Second, signals that may be shielded by special or high-power jammers
In addition to civilion-grade jammers, some more powerful and more targeted jammers (mostly for military use or specific law enforcement agencies) can also block the following special signals:
1.Radio walkie-talkie signals (such as UHF/VHF bands)
This type of jammer can interfere with the UHF (ultra-high Frequency) and VHF (very high frequency) frequency bands commonly used in radio walkie-talkies, blocking voice communication between walkie-talkies. It is commonly seen in scenarios with extremely high requirements for communication control.
2. Remote control signals (such as drone remote controls, specific remote control devices)
It can interfere with specific frequency bands used by drone remote controls, some remote-controlled bomb devices, etc., preventing the remote control devices from sending instructions to the target. It is mainly used in special fields such as security prevention and control and counter-terrorism.
3. RFID/NFC signals
It can shield RFID (Radio Frequency Identification) and NFC (Near Field Communication) signals. These signals are often used in access control cards, payment cards, electronic tags of goods and other devices. After shielding, it can prevent cheating through micro RFID/NFC devices and is mostly applied in examination rooms, confidential meetings and other occasions that require strict control.
We are a custom manufacturer of signal jammers in China. We have a variety of signal jammers for you to choose from and customize. For any needs, please contact us at info@alasartech-security.com.
