The math you have used assumes the transistor circuit is operating in the linear region i. Am is a relatively simple way to add audio information to a carrier wave so that sounds can be transmitted. Pcb design practical lab experiment for amplitude modulation am with multisim software. The output can be used to simulate the response of lc and tank.
Amplitude modulation am a method of emphasizing data on an alternating current waveform or radio wave wherein the carried transmitted signal varies with reference to the amplitude. Millions of thanks from depths of my heart to every subscriber and visitor. The first three sections of the schematic are the modulation circuit. What are the ideal sine wave generator circuits or ics for. The output can be used to simulate the response of lc and tank circuits. Amplitude modulation and demodulation circuit simulation in multisim. Schematic of the amplitude modulation measurement circuit. This circuit uses two signal generators to simulate an amplitude modulated rf carrierwave. Two signal generators are used in this circuit, one representing a high frequency 200khz rf carrier,vg2, the other signal generator is used to inject a 1khz audio signal.
Amplitude modulation the amplitude of highcarrier signal is varied according to the instantaneous amplitude of the modulating message signal mt. Use the spectrum analyzer to compare this modulator to the one in part 2. Public circuits, schematics, and circuit simulations on circuitlab tagged amplitudemodulation. Amplitude modulation tutorial and am radio transmitter circuit. Remember, for analysis purposes keep the modulation index and frequency the same as part 2, step 3. Public circuits tagged amplitudemodulation circuitlab.
The amplitude modulation is the simplest modulation technique among the wide verity of modulation techniques in use. In early am transmitters the amplitude modulator circuit was a key element of the transmitter. The ad654 changes the frequency of the output based on the voltage level of the input. Am amplitude modulation schematics electronics tutorials. Pcb design for amplitude modulation using multisim software. Amplitude modulation circuit implementation electrical. The amplitude modulation of a high frequency signal is easy to achieve and the demodulation is also simple compared to other techniques. Amplitude modulation circuit implementation for use in. Amplitude modulation is defined as a process in which the amplitude of the carrier wave ct is varied linearly with the instantaneous amplitude. In the drawing, the voltages shown for the two generators are peak values. The circuit was designed to be able to obtain signals via amplitude modulation where the sensitivity and selectivity is fairly good. The original method of electronically encoding sound information on radio waves is called amplitude modulation, or am.
This article shows how you can easily build a very simple modulator circuit, having. Today with software processes and multimode transmitters, the amplitude modulator is likely be contained within an overall modulator circuit that is able to provide a number of different types of modulation. Am modulation and demodulation with circuit and output. Amplitude modulation circuit and block diagram youtube. Then i explain what modulation and amplitude modulation are, and show you how to build a low powered am radio transmitter out of a tl072 dual op amp ic. This site uses cookies to offer you a better browsing experience. The modulating signal is the envelope of the carrier the required bandwidth is 2b, where b is the bandwidth of the modulating signal why am. The capture of data, demodulation, visualization and further signal processing is done by a software, that we developed in java and javafx. High frequency sine waves on the order of a few khz e. It was developed in the first few decades of the twentieth century.
Fm modulation and demodulation circuit multisim live. This circuit uses two signal generators to simulate an amplitude modulated rf carrier wave. Explain briefly in your report how amplitude modulation is accomplished by this circuit. We first modulate the carrier wave, then amplify it. The timing resistors and capacitors give a base frequency value for the ic to work with based on the equation found in the datasheet. Engineering communications, circuit projects, pspice software. Amplitude modulation receiver circuit eeweb community. This video covers the history of the discovery of radio waves, to the creation of simple oscillator based radio transmitters.