To understand the various aspects of amplitude modulation. The term demodulator is used because the demodulation process is considered to be the opposite of modulation. The focus of this lab is to familiarize the student with the modulation and demodulation of an. Introduction to modulation and demodulation free download as powerpoint presentation. In modulation, one characteristic of a signal generally a sinusoidal wave known as the carrier is changed based on the information signal that we wish to transmit modulating signal. The idea is simple, though the notion that it can be used to modulate signals. To understand the theoretical foundations of analog communications as well as of doublesideband amplitude modulation and demodulation dsbam to design the simulink model of the dsbam to analyze each signal in time and frequency domains using time scope and spectrum analyzer. Amplitude modulation definition, types, solved examples. Introduction to modulation and demodulation modulation. In practice, the carrier may be highfrequency hf while the modulation is audio. Amplitude modulation is defined as the process in which the amplitude of the carrier wave ct is varied about a mean value, linearly with the baseband signal. Amplitude modulation and demodulation electrical and computer. Modulation and demodulation this chapter describes the essential principles behind modulation and demodulation, which.
Essentially an amplitude modulated wave consists of a radio frequency carrier a sine wave at one frequency, typically in the radio frequency portion of the spectrum. Build simple am modulator by using crystal oscillator. To generate and observe the dsbam and dsbscam signal. Amplitude modulation is mostly used in the form of electronic communication.
In amplitude modulation theory, the amplitude of a carrier signal is varied by the modulating voltage, whose frequency is invariably lower than that of the carrier. In this chapter we will discuss ways of demodulating am, cw, fm, phase, and pulse modulation. The responses are compared against the theoretical. Build simple envelope detector for am demodulation. Amplitude modulation is one of the oldest forms of modulation. As a result of the theoretical approach to the amplitude modulated noise, the signaltonoise ratio of the demodulated signal is proportional to the. This principle is at the heart of amplitude modulation. The circuit in which restoration is achieved is called the detector or demodulator both of these terms are used in neets. In amplitude modulation the amplitude of high frequency sine wave carrier is varied in accordance with the instantaneous value. Amplitude modulation theory frequency spectrum power.
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