Table of Contents
- 1 Why does the modulation index need to be less than 1 in double sideband carrier modulation technique?
- 2 What is constant in phase modulation?
- 3 Why the modulation index is kept within limits in amplitude modulated signal transmission?
- 4 What does a modulation index of 1 mean?
- 5 Which of the following is modulation frequency and phase is constant?
- 6 What is the difference between high level and low level modulation?
Why does the modulation index need to be less than 1 in double sideband carrier modulation technique?
For instance, if this value is less than 1, i.e., the modulation index is 0.5, then the modulated output would look like the following figure. As the value of modulation index increases, the carrier experiences a 180° phase reversal, which causes additional sidebands and hence, the wave gets distorted.
What is constant in phase modulation?
Phase modulation (PM) is a modulation pattern for conditioning communication signals for transmission. The peak amplitude and the frequency of the carrier signal are maintained constant, but as the amplitude of the message signal changes, the phase of the carrier changes correspondingly.
What does low modulation mean?
low-level modulation: Modulation of a signal, e.g., a carrier, at a point in a system or device, such as a radio transmitter, where the power level is low compared to the final output power. (
Why the modulation index is kept within limits in amplitude modulated signal transmission?
Modulation index is defined as a measure of the extent of modulation done on a carrier signal wave. Its value is generally kept less than 1 for practical purposes to avoid over modulation which leads to distortions in the modulated signal and then makes it very hard to demodulate and extract the modulating signal.
What does a modulation index of 1 mean?
A modulation index of 1 is the maximum level of modulation that can normally be applied and occurs when the envelope increases by a factor of 1, i.e. twice the steady state value, and falls to zero.
Which of the following is constant in the case of frequency modulation?
6. Which of the following is constant in the case of frequency modulation? Explanation: In frequency modulation, the carrier wave has constant amplitude and the modulating wave information is conveyed by the amplitude of the carrier waves.
Which of the following is modulation frequency and phase is constant?
Amplitude Modulation (AM) is a modulation in which the amplitude of the carrier wave is altered in accordance with the instantaneous amplitude of the modulating signal, keeping phase and frequency constant. With AM, the strength of the signal varies in order to incorporate sound information.
What is the difference between high level and low level modulation?
In low level modulation, modulation takes place prior to the output element of the final stage of the transmitter. For low level AM modulator class A amplifier is used. In high level modulators, the modulation takes place in the final element of the final stage where the carrier signal is at its maximum amplitude.