This technology originates from WWII. RF Jammer breaks the uplink/downlink between communication devices including drones and mobile phones. Many branded flight controllers for drones have their systems fail and employ the return to home function. RF Jammer works effectively but does have collateral effects interfering with other frequencies for 2.4G-5.8G mobile phone or ambulance communications etc. For the drone datalink frequency 433 MHz, 915 MHz, & 1.2 GHz, RF Jammer needs more power & amplification to cover these bands. In most countries, RF Jammer only can be used by the Military, Authorised Law Enforcement Section, Government, and Police industry.