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In phase modulation the amount of phase shift in the carrier signal depends on the of the modulating signal and the rate of phase shift depends on the of the modulating signal?
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∙ 14y ago
Amplitude
Frequency
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∙ 14y ago
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What is the Comparison of frequency modulation and amplitude modulation?
I will answer this in the simplest way I know in the application I use it in; this would be in audio applications. Amplitude modulation is modulation of a carrier source's loudness; Frequency modulation is modulation of a carrier source's pitch; and Phase modulation is modulation of a carrier source's duty cycle/symmetry/timbre. One can often notice that all 3 modulation types relate in some way with another in that when frequency rises and falls it typically makes it favorable for either a rise in loudness or timbre. The most analog way to understand it in nature is typically your small vowel sounds like "iiiiiiiiiiiiii" as in the American-English word 'easy' and 'eeeeeeeeeeee' as in 'edge' are easier to say with loudness at higher pitches; medium vowel sounds like 'uuuuuuuuuuu' as in 'Utter' or 'sOn' and 'aaaaaaaaaaaa' as in 'Awe' *chuckles* are easier to say with loudness at medium pitches; large vowel sounds like 'ooooooooooo' as in 'Oh' and 'uuuuuuuuuuuu' as in 'rUne' are easier to say with loudness at lower pitches. AM is often known as 'tremolo'; FM is often known as 'vibrato'; PM is often known as 'wow'; AM/FM is 'vibremelo' and fill in the blanks for the other sub-variants. Maikel Stellerfield
What is the time signature of bach's concerto no 5?
Beethoven's Symphony No. 5 is in the key of C minor, but there is a reasonable amount of modulation across the movements. The first movement begins in C minor but modulates to the relative major (E-flat major), the second movement is in A-flat major and the third movement is in C major. But as I said, there is a reasonable amount of modulation.
How much does a song writer makes?
no set amount; depends on the marketability of the songs
What is the amount of money spent on clothes each year?
Depends age of person or child and how much you need and depends on where you shop for clothes.
How much does it cost to get Lecrae for concert?
The amount to get Lecrae for a concert depends. There is no confirmed number.
If the frequency in AM does not change then how are these sidebands formed?
The process of changing the amplitude of the "carrier" so as to add information to it (modulation) doesn't change the frequency of the carrier. But it does create energy at two other newfrequencies.The new frequencies are equal to (carrier frequency) plus and minus (the modulating frequency). These are referred to as the upper and lower sidebands.The upper sideband is an exact copy of the modulating signal, but with every component of it shifted up by an amount equal to the carrier frequency. The lower sideband is a mirror image of the upper sideband, with every frequency component in it reflected about the carrier frequency.
How control dc motor using micro controller?
The speed of the motor depends on load, voltage and current. The speed can be maintain by using a method called Pulse code modulation (PWM). By changing (modulating) the width of the pulse applied to the DC motor we can increase or decrease the amount of power provided to the motor, there by increasing or decreasing the motor speed. mean we have to just change the duty cycle of modulating output.
What is the Comparison of frequency modulation and amplitude modulation?
I will answer this in the simplest way I know in the application I use it in; this would be in audio applications. Amplitude modulation is modulation of a carrier source's loudness; Frequency modulation is modulation of a carrier source's pitch; and Phase modulation is modulation of a carrier source's duty cycle/symmetry/timbre. One can often notice that all 3 modulation types relate in some way with another in that when frequency rises and falls it typically makes it favorable for either a rise in loudness or timbre. The most analog way to understand it in nature is typically your small vowel sounds like "iiiiiiiiiiiiii" as in the American-English word 'easy' and 'eeeeeeeeeeee' as in 'edge' are easier to say with loudness at higher pitches; medium vowel sounds like 'uuuuuuuuuuu' as in 'Utter' or 'sOn' and 'aaaaaaaaaaaa' as in 'Awe' *chuckles* are easier to say with loudness at medium pitches; large vowel sounds like 'ooooooooooo' as in 'Oh' and 'uuuuuuuuuuuu' as in 'rUne' are easier to say with loudness at lower pitches. AM is often known as 'tremolo'; FM is often known as 'vibrato'; PM is often known as 'wow'; AM/FM is 'vibremelo' and fill in the blanks for the other sub-variants. Maikel Stellerfield
Why you need modulation?
It might be helpful to have a working definition of modulation before making a statement as to why it is needed. In fact, with an understanding of what modulation is, it will be obvious why it is included in electronic communications.Modulation is the "message" or the "intelligence" that is impressed on a radio frequency (RF) carrier. When we transmit a signal, we generate a carrier frequency, and then we modulate it. We "add" the message or the information we wish to transmit by modulating the carrier in some way. There are at least a dozen different modulation schemes ranging from simple to real head scratchers. They either modify the amplitude, the frequency or the phase of the carrier. Let's look at a few.The simplest modulation technique is taking the transmitted signal and turning it on and off. It is "keyed" to send a series of pulses. Morse code uses on-off keying. In this method of modulation, no modification of the RF carrier signal itself is made. It is simply switched on and off. (It could be looked at as amplitude modulation with the carrier either at zero amplitude or at "maximum" amplitude with nothing in between.) A series of pulses can be transmitted. With Morse code, a short "on" period will send a dot or "dit" out. If we extend the "on" period a bit, we can send a dash or "dah" out. Nothing real sophisticated here, but basic and effective communication. There are obvious limits to how fast information can be transmitted with this modulation scheme. (But don't tell the hams who still use it!)Most of us are familiar with AM radio. AM is amplitude modulation. The amplitude of the RF carrier is modified to modulate it. The amplitude of the modulating signal will determine the amount that the amplitude of the carrier is changed. (The volume of the modulation determines how much the amplitude of the carrier is changed. The frequency of the modulating signal determines the rate of change of the amplitude of the carrier. (The frequency of the modulation determines how fast the amplitude of the carrier is changed.). The frequency of the carrier is held constant through all this.How about FM? In frequency modulation, the amplitude of the carrier is constant. It's left alone. But the frequency of the RF carrier is changed. It is swung above and below where it sits (it's assigned center frequency) at a rate proportional to the frequency of the modulating signal, and at an amount proportional to the amplitude of the modulating signal. In FM single sideband, the carrier frequency and the frequencies above the carrier are transmitted and the frequencies below the carrier are suppressed (upper sideband transmission). Or the frequencies below the carrier are transmitted with the carrier and the upper frequencies are suppressed (lower sideband transmission). In conventional television, the video signal is single sideband, suppressed carrier. It's like "regular" upper sideband transmission except the carrier signal is suppressed. Sideband transmission "saves" space on the RF spectrum. And it works because we really don't need "all" of the FM signal to demodulate the signal at the receiver.Other forms of modulation become more complex. CDMA (code division multiple access), TDMA (time division multiple access) and other methods are used in cell phones to modulate the carrier so the digital data stream can be impressed on the carrier.Modulation is the addition of intelligence to a carrier signal. It's the message. Modulation is necessary because the point of communication is getting the message through.A Simple answer:Simply this... Any communications medium: e.g. Free space - radio waves, Air - Sound waves or radio waves, Optical Fibre - Light, Copper Wires Electrical Anergy (with frequency limits of the copper wire construction) is made for a certain type of signal. But if the signal we want to send is not compatible with the medium, then it does not travel well.Modulation changes the information we want to send from it's original form, into one that is more compatable with the medium we are trying to use.For example, your computer speaks digital over a TCP/IP LAN which requires CAT 5 or better rated cables,, but to connect to your internet service provider (ISP), you need to send the signal over the wires of the telephone company (made for voice tones). To make this connection, and ADSL modem (modulator/demodulator) is used to convert the data into audio tones, which pass over the telephone line, and at the far end are converted back to digital to join the service providers network. in the reverse direct the ISP does the same, and the signals are de-modulated, back to data for your network.Or in simple terms, Its about best use of the medium. Everything else is just a away of doing it. And there are a lot of possible ways to choose.
What are the advantages and disadvantages of double sideband suppressed carrier modulation?
Amplitude modulation of a carrier results in a transmitted signal consisting of the carrier, plus an 'upper sideband' and a 'lower sideband', spaced above and below the carrier frequency by the frequency of the modulation.The bandwidth of the whole signal is double the modulation frequency. Also, the power in the carrier is constant, and power must be added in order to radiate the sidebands.All the receiver needs in order to extract the information from the signal is one complete sideband, and knowledge of the frequency and phase of the carrier. Economically speaking, the carrier is wasted power, and the other sideband is wasted power andwasted spectrum.If you can filter away one of the sidebands before transmission, then you save half of the occupied spectrum, and the receiver has everything it needs to decode the signal. If you can also filter away the carrier ... or at least knock it way down ... before transmission, you can save a lot of power and use it for the remaining sideband, which extends your range for a given amount of power. The receiver still has everything it needs, as long as it can pick up a sniff of carrier ... enough to derive the carrier frequency and phase.This mode is known as "Single Sideband Suppressed Carrier". It's exactly how the video portion of standard NTSC analog TV was transmitted, throughout all of human history until June 2009.
How ppm differs from FM?
PPM=Pulse Position Modulation is suited for data communications via optical fiber or short distance line-of-sight as in radio control models. A pulse is encoded by placing it in a specific position in time. Proper sync is required and transmission distortion can render it useless. FM=Frequency Modulation which is more suited for audio communications as in broadcast radio or personal communicators. The modulation of a carrier is accomplished by causing the frequency of the carrier to vary as a function of the audio. The speed of the variation is the frequency of the audio and the amount of the variation is the amplitude of the audio.
What is the number of waves in a certain amount of time called?
Modulation
The amount of frequency shift during modulation is called?
Frequency shift keying in digital communication and Frequency modulation in analog communication..........
Difference between narrow band angle modulation and wide band frequency modulation?
Preface:In communications, modulation is the process of "mixing" one signal (the one you intend to transmit, called the "message" and often simplified as being a simple sinusoid) with another (called the "carrier" and also often simplified as being a sinusoid) in some form. In Amplitude Modulation (AM), the two are simply linearly multiplied, ie:u(t) = Ac(1 + k*m(t))*cos(2*pi*fc*t)where Ac represents the amplitude of the carrier signal, k is a modulation index, fc is the carrier frequency, and u(t) represents the modulated signal. Through the trigonometric properties of sinusoids, it is possible (and in the case of AM fairly straightforward) to recover the original message signal m(t) in the absence of noise.Both Frequency Modulation (FM) and Phase Modulation (PM) are forms of Angle Modulation, in which your signal of interest m(t) modulates the angle of the carrier wave, which is a type of nonlinear modulation. This can be generalized as:u(t) = Ac*cos(2*pi*fc*t + p(t))where p(t) is linearly related to m(t), your message, and itself represents an angle shift. (For now it doesn't matter whether p(t) is modulating frequency or phase.)Assume p(t) described above is a sinusoid out of phase with the carrier by 90 degrees, specifically that the carrier is a cosine wave and the angle modulating message p(t) is a sine wave. Using the simple trigonometric identitycos(a + b) = cos(a)cos(b) - sin(a)sin(b)we can rewrite u(t) in its in-phase quadrature formu(t) = Ac[ cos(p(t))*cos(2*pi*fc*t) - sin(p(t))*sin(2*pi*fc*t) ]Trigonometrically speaking (see first-order Taylor Series approximation for further reading), for very small (close to zero) values of t in cos(t), cos(t) is almost 1, and sin(t) is almost t. If we assume that p(t), the angle modulating signal message, always has a very small value (nearly zero), we can reasonably simplify the modulated signal to the form:u(t) Ac[ cos(2*pi*fc*t) - p(t)*sin(2*pi*fc*t) ]which, if you compare with the form of the AM signal, is very similar. In fact, this "narrowband" angle modulation, which assumes a narrow range of angles possible, is nearly identical to the functionality of AM and therefore consumes almost the same amount of signal bandwidth and is analyzed in a very similar manner. This is because a first-order approximation (which narrowband is an example of) is linear and therefore is fundamentally the same as AM.Physically speaking, however, using a narrowband angle modulation technique is not reliable and provides little benefit over an AM technique. It consumes the same amount of signal bandwidth as AM and is just as susceptible to noise. (Consider some additive spectral noise variable, taken with our assumption that p(t) was extremely small, will indicate that the received signal will be unrecognizably different than the transmitted signal.)Wide band angle modulation, on the other hand, does not make this simplifying assumption that angles are small (first-order approximation). Without these assumptions, signal analysis is much more complex, and involves solving Bessel functions for multiple values of the message signal across the intended spectrum. However, because of its true nonlinearity, wide band angle modulation is much more resilient to noise than is narrowband/AM and consumes much more bandwidth.
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.
What is the number of waves produced in a certain amount of time called?
Modulation
How do you make a musical Tesla coil?
Solid state coils are particularly well suited to audio modulation because of the very high level of control over the operation of the tesla system. There are many ways of modulating a SSTC (solid state tesla coil), the 2 most popular being AM (amplitude modulation) and what i will call "PRF Modulation". PRF stands for pulse repitition frequency. The reason these 2 modulations exist, is because there are 2 (actually more) distinct types of SSTC. Those that can produce a continuous spark output (that is, a flame like plasma that exists at 100% duty cycle) and those that make what appear to be a continuous spark, but are rather producing sparks at several hundred times per second with a rest between each spark event. The first (continuous) type of SSTC lends itself to audio modulation. Normally the output spark is a silent plasma flame. By modulating the amount of power put into the plasma flame, we can modulate the physical volume of the plasma. Modulating the size of the plasma will cause the expansion/relaxation of air surrounding the plasma, thus producing sound waves.
