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The five pulses

The five pulses used in this experiment are shown in Figure 6 .

Figure 6. Five pulses with additive sinusoids.
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Unlike in the previous two cases shown in Figure 1 and Figure 4 , each of these pulses has a different shape from the others. In other words, in theprevious two cases, each pulse simply looked like a longer or shorter version of the other pulses. That is not the case in this example.

(Note however that the third pulse in Figure 6 looks just like the third pulse in Figure 4 . They were created using the same parameters. However, none of the other pulses in Figure 6 look like the corresponding pulses in Figure 4 , and none of the pulses in Figure 6 look like the pulses in Figure 1 .)

Spectral analysis results

Figure 7 shows the result of performing spectral analysis on the five time series containing the pulses shown in Figure 6 .

Figure 7. Spectral analyses of five pulses.
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Peaks for first two pulses are now resolvable

When we examine the code, you will see that the frequency separation for the first two pulses has been increased to the reciprocal of the pulse length ineach case. This results in the two peaks in the spectrum for each of the first two pulses being resolvable in Figure 7 .

Third pulse hasn't changed

The spectrum for the third pulse shown in Figure 7 is almost identical to the spectrum for the third pulse shown in Figure 5 . The only difference is that I had to decrease the vertical scaling on all of the plots in Figure 5 to keep the peak in the top plot within the bounds of the plot.

Spectral peaks for last two pulses are closer

When we examine the code, you will also see that the frequency separation for the last two pulses has been decreased to the reciprocal of the pulse length ineach case. This results in the two peaks in the spectrum for each of the last two pulses being closer than before in Figure 7 .

The peaks in the bottom two plots in Figure 7 appear to be resolvable, but we can't be absolutely certain because they are so close together, particularly forthe last plot.

(If you expand the Frame to full screen when you run this program, you will see that the two peaks are resolvable, but I can't do that and staywithin this narrow publication format.)

Expand the horizontal plotting scale

Figure 8 adjusts the plotting parameters to cause the left-most one-fourth of the data in Figure 7 to be plotted in the full width of the Frame in Figure 8 .

Figure 8. Expanded spectral analyses of five pulses.
missing image

The peaks are barely resolvable

Figure 8 shows that the two peaks are barely resolvable for all five of the pulses shown in Figure 6 .

(There is no space between the peaks at the baseline in Figure 8 , but the plots do go almost down to the baseline half way between the two peaks.)

The program named Dsp033

The plots in Figure 7 and Figure 8 were produced by running the program named Dsp033 and plotting the results with the program named Graph03 .

A complete listing of the program named Dsp033 is shown in Listing 14 near the end of the module.

This program is the same as Dsp032 except that the separation between the frequencies of the two sinusoids is the reciprocal of the length of the pulse ineach case.

Questions & Answers

Introduction about quantum dots in nanotechnology
Praveena Reply
what does nano mean?
Anassong Reply
nano basically means 10^(-9). nanometer is a unit to measure length.
Bharti
do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
Damian Reply
absolutely yes
Daniel
how to know photocatalytic properties of tio2 nanoparticles...what to do now
Akash Reply
it is a goid question and i want to know the answer as well
Maciej
characteristics of micro business
Abigail
for teaching engĺish at school how nano technology help us
Anassong
Do somebody tell me a best nano engineering book for beginners?
s. Reply
there is no specific books for beginners but there is book called principle of nanotechnology
NANO
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
s.
fullerene is a bucky ball aka Carbon 60 molecule. It was name by the architect Fuller. He design the geodesic dome. it resembles a soccer ball.
Tarell
what is the actual application of fullerenes nowadays?
Damian
That is a great question Damian. best way to answer that question is to Google it. there are hundreds of applications for buck minister fullerenes, from medical to aerospace. you can also find plenty of research papers that will give you great detail on the potential applications of fullerenes.
Tarell
what is the Synthesis, properties,and applications of carbon nano chemistry
Abhijith Reply
Mostly, they use nano carbon for electronics and for materials to be strengthened.
Virgil
is Bucky paper clear?
CYNTHIA
carbon nanotubes has various application in fuel cells membrane, current research on cancer drug,and in electronics MEMS and NEMS etc
NANO
so some one know about replacing silicon atom with phosphorous in semiconductors device?
s. Reply
Yeah, it is a pain to say the least. You basically have to heat the substarte up to around 1000 degrees celcius then pass phosphene gas over top of it, which is explosive and toxic by the way, under very low pressure.
Harper
Do you know which machine is used to that process?
s.
how to fabricate graphene ink ?
SUYASH Reply
for screen printed electrodes ?
SUYASH
What is lattice structure?
s. Reply
of graphene you mean?
Ebrahim
or in general
Ebrahim
in general
s.
Graphene has a hexagonal structure
tahir
On having this app for quite a bit time, Haven't realised there's a chat room in it.
Cied
what is biological synthesis of nanoparticles
Sanket Reply
what's the easiest and fastest way to the synthesize AgNP?
Damian Reply
China
Cied
types of nano material
abeetha Reply
I start with an easy one. carbon nanotubes woven into a long filament like a string
Porter
many many of nanotubes
Porter
what is the k.e before it land
Yasmin
what is the function of carbon nanotubes?
Cesar
I'm interested in nanotube
Uday
what is nanomaterials​ and their applications of sensors.
Ramkumar Reply
what is nano technology
Sravani Reply
what is system testing?
AMJAD
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
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Source:  OpenStax, Digital signal processing - dsp. OpenStax CNX. Jan 06, 2016 Download for free at https://legacy.cnx.org/content/col11642/1.38
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