Basic knowledge of self-made signal jammers, and what determines the signal shielding ability?
Lately, the internet has been paying more and more attention to signal jammers, especially how to create your own. jammermfg and our R&D team decided to make our own guide. It's important to remember that building such a complex instrument is very difficult and requires specialized electronics skills and knowledge.
High power jammers can cover entire buildings. This is more widely used in correctional institutions. A wider system of jammers and video surveillance was installed as part of the 300 million peseta project. Not only can it knock out cell phone signals at New Bilibis Prison (NBP) Building 14, where high-profile inmates are held, but it can take down the entire high-security building as well. The project also includes a generator system to allow high power mobile phone jammers and CCTV systems to continue operating without mains power. Make the defense of the prison more comprehensive.
First of all, you should know that there are 3 ways to interfere with cell phone signals.
1. Spoofing (sending false signals to the device, shutting down or otherwise malfunctioning of the device)
2. DoS (denial of service, signal band full of wireless junk, replace normal signal with if unable to replace and open - or omit)
3. TEMPEST (EMF) shielding (blocks all incoming and outgoing signal objects with air bubbles)
Therefore, our experts resort to the second method. Spoofing is an excellent method, but can be difficult for untrained users to use, requiring precise coordination and control. EMF shields are usually cool, but they tie in one place so you can forget about any kind of portability. Therefore, DoS is still the best option because all mobile devices on the selected frequency may be interfered by the specific area covered by the portable jammer. If you want to extend the coverage of a jammer and its signal blocking capabilities, then what you need is an RF amplifier unit. The greater the power of the signal blocker, the larger the radius of its blockage. As you can imagine, the cost is battery runtime. More power means shorter battery life.
In the electronics market there are many gain level units to choose from (7 dBm, 17 dBm or even 20+ dBm). But keep in mind that a more powerful amp requires a bigger and better power supply. A transmitting antenna is a means of transmitting the signal generated by a jammer. The main characteristic of the antenna is the VSWR (Voltage Standing Wave Ratio). This is necessary because the return loss of the antenna is small if the antenna has a VSWR of 3 or less.
Jammer experts use SMA antennas because they can be easily removed and replaced. Note that unless you're using a cell phone jammer on your TV remote, it's best to use an omnidirectional antenna.
The power supply is what powers your jammer, cell phone jammers typically operate on 5VDC. Therefore, lithium-ion batteries can be used to power the piece. It can also be powered by an AC adapter. There are two types of power supplies: voltage doublers with switched capacitors and inductor-based boost regulators. The first is a simple, effective but unregulated solution. So you need an LDO controller to remove the voltage. The second type is regulated, but is more expensive, more complex, and requires precise specifications of all components to function properly. Our fabricators use Boost Control for their builds. It takes time and effort, but it works well. AC-DC and DC-DC adapters are available for almost all types of mobile signal jammers.