This document discusses FM transmitters and receivers. It begins with an introduction stating that FM transmitters send frequency modulated waves through a band, while receivers receive the modulated signal and demodulate it to the original signal. It then explains frequency modulation and how the carrier frequency is varied based on the modulating signal. It describes the key components of an FM transmitter, including a crystal oscillator, phase modulator, frequency multiplier, power amplifier and antenna. It also briefly outlines the components and functioning of an FM receiver. Finally, it lists some key advantages and disadvantages of FM, as well as applications such as radio broadcasting, mobile radio, TV and cellular communication.