0
2, 4, 6, 8, 10 it depends on the amount of modulation. 100%
1 on each side, 200% 2 sidebands on each side.
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Why we need high power to generate AM signal and low power to generate FM signal?
The reason FM has lower power and AM has higher power is because the more power that an AM signal has, the farther it will go, but FM does not work that way. AM waves can bounce off of the atmosphere, especially at night. This is the reason that you can hear AM stations from far away at night. FM, on the other hand, can't bounce. FM waves only go in a straight line from the tower and no matter how much power you transmit with, an FM wave will only go a short distance. AM Waves can travel through trees and buildings, and FM can't.
What determines the amount of deviation of an fm signal?
FM or frequency modulation is a means to vary the frequency withing a set basic frequency and transmit it. FM radio demodulate the frequency extracting the signal that made the frequency shift at the source.
What is the need for limiter in FM receiver?
The limiter clips the top and bottom of the FM signal to remove any AM signal or static that was picked up. This prevents the FM discriminator from seeing those unwanted signals and inadvertently converting them to audio, scrambling the intended audio signal. Simply put, the limiter blocks interference and static making FM reception very clean.
What is the difference between FM transmitters?
Fro transmitting FM signals from one point to another,one need to have a full system that transforms your signal. The FM transmitter and FM modulator are two parts of this system and they are both necessary in making the system function as desired. The transmitter is the part that dissipates the FM signal into the air so that it can be received by antennas somewhere else. The FM modulator, on the other hand, is responsible for piggybacking the signal onto the carrier signal. Refer american-writers.org for more information.
Why power amplifier used in FM transmitter?
Amplifier is used in an FM transmitter to increase the level of a signal suitable for transmission
What is narrow band FM and how a narrow band FM generate?
If the modulation index of FM is kept under 1, then the FM produced is regarded as narrow band FM. Lower the modulation index, lower the no. of significant sidebands are produced (with reference to bessel function). So lower the no. of significant sideband, lowerer will be the bandwidth of the resulting FM prduced. Sometimes, Narrow Band FM is regarded as, when the significant energy in FM occupies the same bandwidth as ordinary AM with the same modulating signal.
Why we need high power to generate AM signal and low power to generate FM signal?
The reason FM has lower power and AM has higher power is because the more power that an AM signal has, the farther it will go, but FM does not work that way. AM waves can bounce off of the atmosphere, especially at night. This is the reason that you can hear AM stations from far away at night. FM, on the other hand, can't bounce. FM waves only go in a straight line from the tower and no matter how much power you transmit with, an FM wave will only go a short distance. AM Waves can travel through trees and buildings, and FM can't.
Why FM have infinte number of sidebands?
It can't. FM (like broadcast AM) has two *sidebands*, one at a higher frequency than the transmitter's carrier, one at a lower frequency. The modulating signal (voice, music, etc) of any trasnmitter creates one or more pairs of side frequencies within the two sidebands. A broadcast AM signal can only produce two side frequencies, so an AM transmitter at 1.5 MHz, with a 1 kHz modulating tone (fm), would put out its carrier (fc) at 1.5 MHz, a lower side frequncy at (1.5 - 0.001) = 1.499 MHz, then its carrier at 1.5 MHz, and then the upper side frequency at (1.5 + 0.001) = 1.501 MHz. The AM signal can never be wider than twice the highest modulating frequency (fm), spanning from (fc - fm) to (fc + fm), a span of 2 x fm. Be aware that special-purpose AM systems can generate just *one* sideband - we won't go into that amount of detail apart from noting it. FM signals can be wider than twice the highest modulating frequency. The complete analysis needs the mathematical Fourier Transform, but we can think of it this way. Stronger frequency modulation shows up as a larger change in the transmitted signal frequency. An FM signal at 100 MHz, modulated by a 1 KHz tone, *can* put out a lower side frequency at (100 - 0.001) = 99.999 MHz and an upper side frequency at (100 + 0.001) = 100.001 MHz. You could receive this just fine, but it would sound "weak" compared to normal broadcasts. It's possible to increase the frequency shift to (say) five times. Now, the sidebands must extend from (100 - 5x0.001) = 99.995 MHz to (100 + 5x0.001) = 100.005 MHz. How do we account for the original 1 KHz tone creating a bandwidth of 2x5 kHz? The answer is that we actually have *five* lower side frequencies, at -5, -4, -3, -2, -1 kHz below the carrier, and *five* upper side frequencies at +1, +2, +3 +4 and +5 kHz above the carrier. Notice that they are multiples of the original 1 kHz modulating frequency. These can, in fact, be shown on the instrument called a spectrum analyser. Your question? As with broadcast AM, an FM signal has only two sidebands. In FM, the strength of modulation (the modulation index) controls the number of individual side frequencies, and thus the total bandwidth of the signal. Can an FM signal have *infinite* numbers of side frequencies? Not really. It can have a *very large* number of side frequencies with very great modulation strength. In practice, this would take up *a lot* of the FM radio band, so broadcast FM commonly uses a maximum modulation index of 5.0. This means that a fully-modulating 15 kHz signal would give a bandwidth of -(15 x 5) to +(15 x 5) kHz, which is +/- 75 kHz.
A modulated waveform that contains a carrier plus two sidebands for each modulation frequency is a description of?
Both AM and narrow-band-FM.
Differentiate FM signal from AM signal?
FM = Frequency Modulation; AM = Amplitude Modulation; each being a technique by which the speech signal is imprinted onto the carrier signal (the one to which you tune the radio). FM is a higher frequency than AM. FM also only uses the 2.7hz upper side band of the frequency while AM utilizes the entire 6hz both the LSB, USB and the .6hz carrier wave. That allows AM to travel farther than a FM signal.
Why you convert FM signal to IF frequency?
Mix it with a local oscillator whose frequency is (the IF frequency) away from the frequency of the FM signal you're interested in.
How does a high-power FM transmitter work?
Summary: An FM transmitter has an oscillator that generates the carrier RF signal. Frequency modulation takes place at the oscillator stage. The modulated signal is then sent through some filters and then finally amplified by a class C power amplifier, and then delivered to the antenna. An FM transmitter has an oscillator that generates a carrier signal on a desired frequency. But something like a voltage controlled oscillator is used so that the oscillating frequency can be changed by a modulating signal. When there is no modulation, the oscillator runs at it assigned frequency (called a center frequency). The voltage that is controlling the frequency at which it is running is constant. By applying the volage of a modulating signal to that "controlling" voltage, the frequency of the signal can be caused to vary above and below its assigned center frequency in a way that is directly proportional to the modulating signal. It is shifted above and below its assigned center at a rate proportional to the frequency of the modulating signal and at an amount proportional to the amplitude of the modulating signal. This takes up a bit of what is called bandwidth on the electromagnetic spectrum. The modulated FM signal appears as a "group" of frequencies around that center frequency with the sub-group of frequencies about the center being called the upper sideband, and that sub-group below the center being called the lower sideband. Almost all of the power in the generated signal is carried in these sidebands. This RF signal is them amplified by a high power RF amp, and the (now) high-powered FM signal is then sent via a transmission line to an antenna, from where the signal radiates into space. A link is provided to the Wikipedia article on FM modulation. Surf on over and check out the drawings and the little "moving pictures" to get a handle on FM. (No static at all!)
Why are FM tones used in ASSR?
boz there is lesas interferance to the signal as a signal travels...............
How is FM transmitted?
the digital signal is converted to analog signal after using by transmitted antenna
Why is amplitude of demodulated FM signal much less than modulated signal?
because demodulated FM is an audio signal, which the frequency is much smaller that is why it can be transmitted alone. It need carrier which has large frequency. Modulated signal is an audio signal + carrier that is why the amplitude is higher.
Why FM is good than am in communication?
The FM signal is more amune to static in the atmosphere than AM signals.
How does the frequency change in a FM transmitter?
-- the modulation index varies -- the instantaneous deviation varies -- the amplitude of the carrier component varies -- the spectrum of sidebands varies -- the total occupied bandwidth varies
