Yes, absolutely -- you can re-arrange the formula that way to solve for m given a measured value of N. This is actually how this measurement is normally made using a spectrum analyzer. Thanks!
I’m struggling understanding where the side bands come from. If you are modulating the carrier, and the only thing changing is the amplitude, why would there be other frequencies involved?
Side band refers to the "bands" of frequencies on the X axis to the left and/or right of the carrier. The X axis is frequency and Y axis is "energy" of each shown frequency.
Every video explanation I look at just states “here are the side bands of different frequencies” and leave it at that. If the intelligence is in different frequencies its frequency modulation. The 1000hz modulation is in the magnitude (amplitude) of the fixed frequency wave. Not the side bands. Why is it always presented this way?
Hello, just to point out that the amplitude of each sideband is half of the amplitude of the sinusoid: F{ Am*cos(ŋ*t) } = Am/2 [ @(f+ŋ) + @(f-ŋ) ] with @ as the dirac delta dist. Great Video
There are upper and lower sidebands, or side frequencies. The UPPER sideband is made up of the SUM of the carrier plus the modulating frequencies, while the LOWER sideband is the DIFFERENCE between the carrier and the modulating frequencies. Modulation, whether amplitude (AM), frequency (FM), or phase (PM) always involves the production of sidebands.
@@manfredcaranci6234 why though? in case if AM, we are not changing the frequency of carrier signal... we are just changing its amplitude by a factor of modulating signals amplitude (Ac + Am or Ac - Am)
very good man! I would like just o ask something: I don't know if it is a misunderstanding mine or some mistake on the presentation, but I saw a contradition between the 3:30 and 4:56. On 3:30 we have a low signal changing for m=0.1 but on 4:56 a highly changing amplitude of spectrum for the same value of m. How to understand this?
Good question. The graph at 3:30 shows the signal in the *time domain* (power vs. time) and the graph at 4:56 shows the signal in the *frequency domain* (power vs. frequency).
Does not compute. At 2:42 in the time domain, the blue line (carrier) amplitude increases and decreases with time. Amplitude of the carrier frequency is clearly changing/modulating. At 4:22 in the frequency domain, the blue line representing the carrier at that frequency is suddenly now a fixed value. Further on at 5:16, the carrier amplitude is described as constant. Both cannot be true. Many people struggle with this. Just saying.
The video does assume a certain amount of background knowledge - if you have suggestions about what "pre-viewing" content might have been helpful, please let us know!
I wish these videos (+FM) could be out 1 year ago... so good
Thanks for creating this video series.
But at timestamp 4:40, you need NdB as the input to the formula.
So as m = 2 * 10^( NdB / 20 )
Yes, absolutely -- you can re-arrange the formula that way to solve for m given a measured value of N. This is actually how this measurement is normally made using a spectrum analyzer. Thanks!
I’m struggling understanding where the side bands come from. If you are modulating the carrier, and the only thing changing is the amplitude, why would there be other frequencies involved?
Side band refers to the "bands" of frequencies on the X axis to the left and/or right of the carrier. The X axis is frequency and Y axis is "energy" of each shown frequency.
@poorman8317 did you got the answer , cauz I'm stuck with the same point.
Carrier + modulation into a mixer sum and difference gets ur sidebands
I think its their Harmonics, depending on modulating signsl
Every video explanation I look at just states “here are the side bands of different frequencies” and leave it at that. If the intelligence is in different frequencies its frequency modulation.
The 1000hz modulation is in the magnitude (amplitude) of the fixed frequency wave. Not the side bands. Why is it always presented this way?
Wow, this video helped me understand my AM modulation lab so much. Thank you 🙏
Glad it was helpful - thanks for the feedback!
This is very helpful to understand the basics of AM. Thanks.
Thank you!
Thanks for your presentation , it's very rich and simple to understand
Thanks! Appreciate the feedback!
Thank you sir ❤️❤️❤️❤️ from 🇮🇳 india
Hello, just to point out that the amplitude of each sideband is half of the amplitude of the sinusoid:
F{ Am*cos(ŋ*t) } = Am/2 [ @(f+ŋ) + @(f-ŋ) ]
with @ as the dirac delta dist.
Great Video
Thanks!
Amplitude of sideband is not strictly 1/2 of carrier. You can change the amplitude by changing m ratio
why you draw the rf signal in sine wave, I mean the most common case, it is not sin/cosine?
Thanks for this. Really helped with my signals coursework
sir,will u explain me the sidebands please? i've many doubts about sidebands.
There are upper and lower sidebands, or side frequencies. The UPPER sideband is made up of the SUM of the carrier plus the modulating frequencies, while the LOWER sideband is the DIFFERENCE between the carrier and the modulating frequencies. Modulation, whether amplitude (AM), frequency (FM), or phase (PM) always involves the production of sidebands.
@@manfredcaranci6234 why though? in case if AM, we are not changing the frequency of carrier signal... we are just changing its amplitude by a factor of modulating signals amplitude (Ac + Am or Ac - Am)
very good man! I would like just o ask something: I don't know if it is a misunderstanding mine or some mistake on the presentation, but I saw a contradition between the 3:30 and 4:56. On 3:30 we have a low signal changing for m=0.1 but on 4:56 a highly changing amplitude of spectrum for the same value of m. How to understand this?
Good question. The graph at 3:30 shows the signal in the *time domain* (power vs. time) and the graph at 4:56 shows the signal in the *frequency domain* (power vs. frequency).
@@pauldenisowski then a low amplitude proportion in time domain can correspond to a high amplitude proportion in frequency domain?
Consider adding Greek 101 as a prerequisite.
(laughs) γηράσκω δ᾽ αἰεὶ πολλὰ διδασκόμενος :)
Greetings from Greece
Thank you Senpai.
Does not compute.
At 2:42 in the time domain, the blue line (carrier) amplitude increases and decreases with time. Amplitude of the carrier frequency is clearly changing/modulating.
At 4:22 in the frequency domain, the blue line representing the carrier at that frequency is suddenly now a fixed value. Further on at 5:16, the carrier amplitude is described as constant.
Both cannot be true. Many people struggle with this. Just saying.
Wow! Very well done! Thank you!
thank
Thanks very very much. Love u
Professional video !
Thanks - I try :)
good thanks
Thanks!
Thank you!
When did you get Brent Spiner to voiceover this? lol
I could never hold a candle to Commander Data :) Besides, if you listen closely, you'll hear me using contractions ...
You might find this video relevant: Amplitude Modulation the Big Picture
th-cam.com/video/ozfGM4ikv5I/w-d-xo.html
This explanation of AM makes too many assumptions to be useful, not to mention it moves too fast.
The video does assume a certain amount of background knowledge - if you have suggestions about what "pre-viewing" content might have been helpful, please let us know!
You have helped me more than you can imagine🥹🥹🥹
Glad to hear it - thanks!