Frequency and Phase Modulation

Angle modulation for transmission of analog signals (frequency and phase modulation) is a widely used method in broadcasting and point to point communication. Frequency modulation is the method of choice for low power point-to-point communication systems, high fidelity audio and music broadcasting and audio component of TV broadcasting. FM is most widely used since it provides excellent signal to noise ratios at the price of increasing the transmission bandwidth. Another major advantage of angle modulated signals is their constant envelope property that makes them more desirable in applications where high power amplification is required using nonlinear amplifiers such as class C amplifiers ant travelling wave tubes. Keywords: angle modulation; frequency modulation; phase modulation; FM radio broadcasting; FM stereo broadcasting; pre-emphasis and de-emphasis filtering