RF amplifiers are electronic devices that increase the power of radio frequency signals. They are essential in various applications, such as communication systems, broadcasting, and radar. By boosting weak signals, RF amplifiers ensure that information can be transmitted over long distances without losing quality. These amplifiers work by taking an input signal and producing a stronger output signal while maintaining the original signal's characteristics. They are designed to operate at specific frequency ranges, making them crucial for devices like cell phones, television transmitters, and satellite communications.