​A common jammer is to shield mobile phone signals by emitting interference signals. By transmitting a high-power signal of a certain frequency, the surrounding electromagnetic environment is severely damaged, and the mobile phone cannot normally obtain and analyze the signal from the base station, thereby achieving the purpose of shielding the mobile phone signal.

​ The wireless communication module is the key link connecting the perception layer and the network layer of the Internet of Things. It belongs to the underlying hardware link and is irreplaceable. There is a corresponding relationship between the wireless communication module and the IoT terminal. However, there are so many types of wireless communication modules that emerge in an endless stream, which is dazzling.

Brief introduction of GPRS, 4G, NB-IOT wireless communication module

​ Inertial navigation is a navigation technology that uses inertial sensitive components or devices on the carrier to measure the carrier's motion acceleration and angular velocity, and calculate the carrier's position, velocity, and attitude angle. Inertial navigation is widely used in aerospace, rail transit, automatic driving, portable positioning terminals and other fields.

​ In electronic circuits, most of them require a DC regulated power supply for driving. For example, in the amplifying circuit, on the one hand, the DC voltage regulator must establish a suitable static operating point for the circuit operation, and on the other hand, it must provide the required energy for the amplification of the signal.