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Amplitude modulation or AM as it is often called, is a form of modulation used for radio transmissions for broadcasting and two-way radio communication applications.
Chapter 5 Amplitude Modulation AM was the first widespread technique used in commercial radio broadcasting. An AM signal has the mathematical form s(t) = Ac[1+kam(t)]cosωct where • m(t) is the basebandmessage. • c(t) = Ac cosωct is called the carrierwave. • The carrier frequency, fc, should be larger than the highest spectral component ...
Hence, we can calculate the value of modulation index by using the above formula, when the amplitudes of the message and carrier signals are known. The modulation index or modulation depth is often denoted in percentage called as Percentage of Modulation. We will get the percentage of modulation, just by multiplying the
Amplitude modulation is defined as the process in which the amplitude of the carrier wave c(t) is varied about a mean value, linearly with the baseband signal. An AM wave may thus be dscribed, in the most general form, as a function of time as follows.
Amplitude Modulation. So far we have developed basic signal and system representation techniques which we will now apply to the analysis of various analog communication systems. In particular, we will study: Amplitude modulation (AM) and its variants; Angle modulation including Frequency modulation (FM) and Phase modulation (PM). •. Let m(t.
1 Amplitude Modulation Principle. The amplitude-modulated wave may be described by the following formula. s(t) = [1 + kam(t)] c(t) = Ac [1 + kam(t)] cos(2 fct); where ka is a constant and is called the amplitude sensitivity. Figures 1.(a)-(b) gives an illustration of the AM process.
Amplitude Modulation (AM) works by varying the amplitude (“strength”) of a carrier signal, in proportion to amplitude of a modulation signal that is to be transmitted to one or more receivers. The carrier signal c(t) is just a sinusoid with a frequency fc and an amplitude Ac. This is mathematically expressed as.
3.2 Amplitude Modulation A sinusoidal carrier wave: AM is defined as a process in which the amplitude of the carrier wave c(t) is varied about a mean value, linearly with baseband signal m(t). AM wave, in its most general form Typically, the carrier amplitude A c and the message signal m(t) are measured in volts, in which case the k
Calculate the modulation index and percentage of modulation of an AM signal, given the amplitudes of the carrier and modulating signals. Define overmodulation and explain how to alleviate its effects.
depth of modulation 100% amplitude modulation is defined as the condition when m = 1. Just what this means will soon become apparent. It requires that the amplitude of the DC (= A) part of a(t) is equal to the amplitude of the AC part (= A.m). This means that their ratio is unity at the output of the ADDER, which forces ‘m’ to a
