amplitude modulation and frequency modulation

Amplitude Modulation - When the amplitude of high frequency carrier wave is changed in accordance with the intensity of the signal, it is called amplitude modulation. In amplitude modulation, only the amplitude..

When the amplitude of high frequency carrier wave is changed in accordance with the intensity of the signal, it is called amplitude modulation..

In frequency modulation, the frequency of the carrier wave is modified in accordance with the amplitude of the modulating wave. The amplitude of the carrier remains unchanged at all times. In other words, the amplitude of the ..

The amplitude-modulated band (AM band) contains the radio waves having frequency of less than 30 MHz or having wavelength of 10 m or more. The lower atmosphere is more or less transparent to radio waves. However, the ionosphere reflects back the radio waves. Thus, a signal emit..

Pulse Modulation - In amplitude modulation and frequency modulation, the modulation was done by sinusoidal signals. In pulse modulation, short pulses may do the modulation of a radio-frequency carrier. The sim..

Need for Frequency Modulation - (i) Various electrical machines and noises cause amplitude disturbance in the transmission of amplitude-modulated wave. This makes the reception noisy. So, there is a need for different type of modulation, which can r..

(i) Various electrical machines and noises cause amplitude disturbance in the transmission of amplitude-modulated wave. This makes the reception noisy. So, there is a need for different type of modulation, which can reduce the noise factor. Frequency mod..

In this type of modulation, E c , w c are kept constant. The phase angle q of the carrier wave is varied according to the modulating wave. The common name for "phase modulation" and "frequency modulation" is "angle modulation". The d..

In amplitude modulation, the sidebands contain the signal. The power in the sidebands is the only useful power. The power carrier by the side bands is only 33.3% even when there is 100% modulation. If modulation is 50%, then power carried by the sideban..

The modulating signal is sampled at the basic rate, usually where f m is the maximum value. The amplitude of the modulation determines the amplitude of the transmitted pulse. The band-width will be great for exact pulse waveform, but may be reduced by a l..