There are three types of Amplitude Modulation Μ= Ac/Am=Amplitude of carrier wave/ Amplitude of modulating signal Types of Amplitude Modulation Φ- phase of the signal at the start of the reference time The Amplitude Modulation equation is given as, High- level Generation – In this technique, the gain of the transmitter final output is amplified. Low- level Generation – In this method of AM, frequency less than the desired frequency is generated and then later amplitude is modulated. There are two methods of Amplitude Modulation For transmission of long, medium and small waves, AM is widely used. It is widely used in electronic communications. The transmission of data by radio carriers with the help of addition of signals in which frequency is kept constant and amplitude is modulated, is known as Amplitude Modulation. The output is small compared to other types of modulations.įor better transmission you need closely placed antennae. It can be used for low power transmitters.įor an expected output, less battery power is required and thus can be used for two-way radio applications. As the only frequency modulation takes place, transmission remains unaffected. The main advantage of FM is, it is less susceptible to noise and other interferences during transmission of signals. Ɵ – is the phase of the modulating signal.ĭeviation of frequency Δf max is given by the expression, Ω m – Angular frequency of the modulating signal. In this method, phases are constrained within the loop to modulate frequency.Ī m – Amplitude of the modulating signal. Phase Locked Loop – This technique provides excellent FM. This method gives only narrow band transmissions. Varactor diode Oscillator – In this technique, a varactor diode is placed within the circuit to modulate frequency. There are many techniques used for Frequency Modulation. As these interferences can easily affect the magnitude of the amplitude but cannot diversify frequency, FM is preferred by users. To overcome the effect of noise and interference with other signals rising due to thunderstorm and eddy currents generated in transmission devices, a method of Frequency Modulation is used. Armstrong, an American electrical engineer. In frequency modulation, the amplitude of the signal is constant but the frequency is modified according to signals being sent. We shall now discuss FM and AM one by one. There are three basic types of modulation,Īs Phase Modulation and Frequency modulation works on the same principle, they are considered as the inter-related. Modulation has wide applications in radio, optics/laser and computer networks. The data is added to the carrier wave by varying its frequency, amplitude, polarization, spin and phase. Usually, a carrier signal has a steady waveform i.e. The process of converting and transmitting the data into radio signals by the addition of information to an optical or electronic carrier signal is called Modulation. The transmission takes place with the help of radio carriers. To transmit these data radio signals are used. The information or the data is available in audio, video, written and in other forms.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |