RF is an abbreviation for radio frequency.
A radio frequency (RF) resonant cavity thruster, also known as an EmDrive, is a hypothesized type of propellant-free thruster that was proposed in 2001 by Roger Shawyer.
The RFU Championship, known for sponsorship reasons as the Greene King IPA Championship from 2013–14, is the second tier of the English rugby union league system and was founded in September 1987. The twelve-side league was known as National Division One and in 2009 changed from semi-professional clubs to fully professional.
rFactor 2 is a computer racing simulator developed by the American independent software firm Image Space Incorporated and released for Windows in 2013. Like its predecessor, rFactor, it is designed to be modified and is used by professional racing teams for driver training and race car development.
RFD-TV is an American pay television channel that is owned by Rural Media Group. The channel features programming devoted to rural issues, concerns and interests.
RF Micro Devices (also known as RFMD or RF Micro), was an American company that designed and manufactured high-performance radio frequency systems and solutions for applications that drive wireless and broadband communications.
An RF module (radio frequency module) is a (usually) small electronic device used to transmit and/or receive radio signals between two devices.