The main function of a cellphone signal jammer is to block wireless signals in a specific frequency band, usually used to prevent mobile phone communications. Its working principle is as follows:
- Transmitting interference signals: The cellphone signal jammer covers these frequency bands by transmitting interference signals that are the same as the target frequency band, thereby blocking the communication between the mobile phone and the base station.
- Shielding range: Different models of cellphone signal jammers have different shielding ranges and frequency bands, but they are mainly concentrated in the frequency bands used for mobile phone communications, such as GSM, CDMA, 3G, 4G, 5G, etc.
Working principle of car key signals
Car key signals mainly use radio frequency identification (RFID) technology or low-power Bluetooth (BLE) technology for communication. Common frequency bands are as follows:
- iRFID: Usually works in frequency bands such as 315 MHz, 433 MHz or 868 MHz.
- BLE: Usually works in the 2.4 GHz frequency band.
- Feasibility of cellphone signal jammers to block car key signals
To evaluate whether a cellphone signal jammer is suitable for blocking car key signals, the following aspects need to be considered:
Frequency band matching
cell phone jammers are designed to block mobile phone signals in a specific frequency band, while the frequency band used by car key signals is different from the mobile phone communication frequency band. Generally speaking, standard cellphone signal jammers do not cover low-frequency RFID bands such as 315 MHz, 433 MHz, or 868 MHz. Therefore, ordinary cellphone signal jammers may not be able to effectively block car key signals.
Power and range
The power and shielding range of cellphone signal jammers are usually designed to cover mobile phone signals within a certain area, but car key signals have lower power and smaller coverage. Therefore, even if a cellphone signal jammer can cover the frequency band used by car keys, its shielding effect may be limited, especially in a larger range.
Special equipment requirements
For the shielding needs of car key signals, there are specially designed car key shielding devices or bags (such as Faraday bags) on the market. These devices are specifically designed for the working frequency band of car keys and are more reliable.
Alternatives
For users who need to block car key signals, the following devices are recommended:
- Faraday bag: This is a bag made of conductive material that can effectively block all wireless signals, including car key signals. Faraday bags are affordable, easy to use, and a simple and effective solution.
- Specialized car key shielding box: There are specially designed shielding boxes on the market that can hold car keys to block their signals. These boxes usually use high-quality shielding materials and have excellent shielding effects.
Although cellphone signal jammers are excellent at blocking wireless signals in specific frequency bands, ordinary cellphone signal jammers are not suitable for blocking car key signals because the operating frequency band of car key signals is different from that of mobile phone signals. In order to effectively block car key signals, it is recommended to use a Faraday bag or a special car key shielding box, which are specially designed for car key signals and can provide more reliable shielding effects. By choosing the right shielding device, users can better protect vehicle safety and prevent security threats such as relay attacks.