Jammer is the research direction

Blocking cell phone signals is very useful. Your child's puberty has arrived; you know that you have no right to order again, so please open your forehead and buy this mobile phone signal jammer, wifi will interfere with you, and will help you secretly. After they use the phone to play games or do some time-wasting things, regardless of their learning situation, you can turn on the phone signal to interfere with the buttons. They will not be able to play games, and you will have the opportunity to communicate with them face to face. Also in schools, blocking cell phone signals would disrupt cheating and continue to check. Take a look (this!!!! Mobile phones and 5G jammers use directional antenna design, which can easily prevent CDMA, GSM, DCS, PCS, 3G and WiFi from moving in a certain direction and prevent directional interference.

https://www.perfectjammer.com/gps-blockers-jammers.html

The jammer can effectively resist drones several kilometers away. Generally, GPS jammers work with drones, and their pilots maintain a certain distance between the drone and the jammer. The farther the drone is from the pilot and the closer to the jammer, the better the effect. The typical effective interference direction is about 15-30 degrees cone shape, protruding toward the front end of the spray gun (this is also affected by the RF frequency band and interference power). This interference weapon is also the main direction of weapon research in recent years. It has the effects of high efficiency, less accidental damage and less loss. Currently, the device can disable enemy drones and GPS weapons.

https://www.perfectjammer.com/all-cell-phone-jammers-blockers.html