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P'=P(1+m^2/2)
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Conclusion about amplitude modulation?
A carrier is used to make the wavelength smaller for practical transmission and to permit multiplexing. The spectrum is used to measure bandwidth (the range of frequencies) and the efficiency (the power in the side-bands compared to the total power) Bandwidth can be predicted using BW = 2 fm where fm = the maximum modulating frequency Efficiency depends only on the modulating index, m (the fraction of the carrier you modulate by) AM is limited to 33% efficiency because the modulation index cannot be increased to > 1.0 without introducing distortion in the receiver.
Why do you use delta-sigma modulation instead of delta modulation?
Delta sigma modulation achieves "noise shaping" that essentially high-pass filters the quantization noise. This reduces the noise power in the baseband so that oversampling can access more bits of useful signal resolution than would be possible in the presence of the unfiltered noise.
What is a SSBSC signal?
Single Side Band Suppressed Carrier. This is a modification of AM (Amplitude Modulation) that both reduces required transmitter power and signal bandwidth. The carrier is first modulated by the signal the same as in ordinary AM, then is sent through a bandpass filter to remove one sideband and the carrier. To demodulate it and recover the original signal the receiver must reinsert the carrier using a BFO (Beat Frequency Oscillator) and Mixer.
What is the function of an attenuator in cro?
An attenuator is an electronic device that reduces the amplitude or power of a signal without appreciably distorting its waveform. attenuator just decrease its amplitude and the attenuator you can take it as a opposite of amplifier. Amplifier just modifies the input signal gives amplified output signal
Is exponential signal an energy signal or power signal?
If the signal is not bounded by a step function, then an exponential signal is neither a power nor an energy signal. So the answer is neither.
What transmmited power when modulation index 0 to 1?
It can be anything at all, from yoctowatts to terawatts. You must state the power output at some modulation index before I can calculate it for some other modulation index. By the way . . . the answer also depends on the method of modulation, which you have not mentioned. For example, with pure FM, the transmitted power doesn't change, regardless of the mod-index.
Why is it desirable to have the modulation index of an AM signal as large as possible without overmodulating?
It uses the maximum power available to the transmitter and makes the signal more readable at a greater distance.
Why amplitude modulation is called as collector modulation?
amplitude modulation using collector modulator gives:More symmetrical envelope• Higher power efficiency• Higher output power• Need higher amplitude modulatingsignal
Compare high level modulation and low level modulation?
IN LOW LEVEL MODULATION THE MODULATING SIGNAL IS APPLIED NEARER THE CARRIER OSCILLATOR N IN HGH LEVEL MODULATION MODULATING SIGNAL IS APPLIED AT OUTPUT OF FINAL POWER AMPLIFIER OR FAR FROM CARRIER OSCILLATOR... IN OTHER WORDS :::: IN HAIGH LEVEL MODULATION THE AF SIGNAL IS APPLIED TO COLLECTOR OR PLATE AS THEIR RESPECTIVE DEVICES..... N IN LOW LEVEL MODULATION AF SIGNAL IS APPLIED AT BASE OR GRID IN TRANSISTOR AND TUBES RESPECTIVILY IN LOW LEVEL MODULATION THE MODULATING SIGNAL IS APPLIED NEARER THE CARRIER OSCILLATOR N IN HGH LEVEL MODULATION MODULATING SIGNAL IS APPLIED AT OUTPUT OF FINAL POWER AMPLIFIER OR FAR FROM CARRIER OSCILLATOR... IN OTHER WORDS :::: IN HAIGH LEVEL MODULATION THE AF SIGNAL IS APPLIED TO COLLECTOR OR PLATE AS THEIR RESPECTIVE DEVICES..... N IN LOW LEVEL MODULATION AF SIGNAL IS APPLIED AT BASE OR GRID IN TRANSISTOR AND TUBES RESPECTIVILY
What is percentage power saving if AM transmitter with modulation index m equals 0.5 is replaced by SSBSC transmitter with same modulation index?
Pt=Pc+2Psf, m=0.5 ,Psf=0.0625, saving in power is 100-6.25 % = 94.75%
Why is AM modulation not an efficient way of modulation?
-- The power output stage in the transmitter must be operated either class A or class B. Whereas in FM the power output stage in the transmitter can operate class C which uses much less power per watt delivered to the antenna. -- For full modulation, audio power is required equal to 1/2 of the RF power of the transmitter output stage. -- At full modulation, 2/3 of the total power arriving at the receiver is at the carrier frequency, which conveys none of the information. -- A receiver designed for AM reception is susceptible to a wide variety of natural and man-made noise.
How does the circuit of a collector modulation work?
The output stage of the transmitter is a high power frequency class C amplifier. Class C amplifiers conduct for only a portion of the positive half cycle of their input signal. The collector current pulses cause the tuned circuit to oscillate or ring at the desired output frequency. The tuned circuit, therefore, reproduces the negative portion of the carrier signal. The modulator is a linear power amplifier that takes the low level modulating signal and amplifies it to a high power level. The modulating output signal is coupled through modulation transformer T1 to the class C amplifier. The secondary winding of the modulation transformer is connected in series with the collector supply voltage Vcc of the class C amplifier. Read more: [http://www.daenotes.com/electronics/communication-system/am-modulators#ixzz2R69fAPRC http://www.daenotes.com/electronics/communication-system/am-modulators#ixzz2R69fAPRC]
Define the bandwidth of a frequency modulated signal?
I believe the bandwidth of ANY signal is defined as the range of frequencies that encompasses 99% of the signal's power. For an AM signal at anything less than 100% modulation, it's 2 x the highest modulating frequency. FM signals aren't that simple to characterize. "Cramer's Rule" says that the bandwidth is 2 x (peak deviation + highest modulating frequency), but as the 'modulation index' increases, that rule becomes a poorer approximation.
Why frequency modulation is preffered over AM?
-- FM is better for the person on the transmitting end, because it's easier and cheaper to generate with high quality. Modulation can be applied in an early stage of the transmitter, at low frequency, low power, and with a small modulation index, and the final signal for transmission can be derived by frequency multiplication and power amplification, without garfing up (corrupting) the signal and producing a lot of intermod. AM must be modulated at the final frequency and power, which requires half as much audio power as final carrier output power, which is expensive. -- FM is better for the person on the receiving end, because most of the radio noise in nature, as well as man-made radio noise, is amplitude noise. If your receiver doesn't care about changes in amplitude, it's immune to a lot of the noise that gets picked up on the way from the transmitter to the receiver.
Why is the output signal affected if the impedance of the amplifier and the load do not match?
A: The signal output will not change it is just that the efficiency of power transfer is effected to less
What opportunities does Clinical research courses offer?
The output signal-to-noise ratio is defined as the ratio of the average output signal power to the average output noise power. From Equation (2.140), we see that the message component in the discriminator output, and therefore the low-pass filter output, is
What is the amplitude of am waves?
The amplitude is the amount of power the transmitter is putting out depending the signal being fed into it from the source. It varies constantly with the signal. It is called amplitude modulation. Modulation of over %100 can cause the transmitter to send harmonics called band splatter.
