I recommend using the course website as your main portal to the videos. You can download the notes, get links to the latest version of the videos, and access many other learning resources. Here is the link: empossible.net/emp3302/
1. For TEM mode, since phase constant = wave number, so isn't the speed going to be affected? And what do you mean by "an infinite medium"? 2. Do evanescent modes appear at the cut off frequency? 3. Why there's a minus sign in the expression of impedance (y-component of E-field & x-component of H-field)? 4. Effective refractive index is less than 1,so wave moves with speed higher than that of light. How's it possible?
1. For TEM, speed is not affected. By infinite medium, I mean a plane wave propagating in a homogeneous medium that is of infinite extent. 2. It makes more sense to talk about evanescent fields in the cladding of a dielectric waveguide. When a mode is cutoff, in fact, the mode still exists, but decays quickly as it propagates. 3. A negative sign may appear for backward waves since the H field has the opposite direction as it did for a forward wave. 4. Excellent question! See Lecture 5e.
The surface current is not 1/2 or even 1/2 of K. The surface current is K. The 1/2 means the magnetic field above an infinite current sheet is 1/2 of K cross n. If you would like to see this equation derived, checkout Lecture 5c here: empossible.net/emp3302/
Dear Professor, thanks for the video. It helps a lot. Question regarding impedance: In page 15, you used transmission line definition to calculate ZTEM=Vo/I=Ƞ d/w. In page 13, you got Ey and Hx, essentially you could you Z=-Ey/Hx to caculate ZTEM= Ƞ. In page 25, you gave ZTM= =-Ey/Hx = Ƞ βm/k. For ZTEM, m=0 ZTM=ZTEM= Ƞ. What in page 13 and 25 are consistent, but not consistent with what in page 15. How to understand that?
The characteristic impedance is not usually E/H. Normally, you would do a line integral of the electric field to calculate voltage across the lines, do another line integral of the magnetic field to calculate the current through the line, then Z=V/I.
@@empossible1577 Thanks for your quick reply. But sorry, I don't get it yet. Also I found I made some small mistakes when I presented the question which may have confused you. Let me re-present the question as below: Question regarding impedance: In slide 15 video time 13:15, you used transmission line definition to calculate ZTEM=Vo/I=Ƞ d/w. In slide 13 video time 9:53, you got Ey and Hx, essentially you could you Z=-Ey/Hx to caculate ZTEM= Ƞ. In slide 49 video time 47:40, you did give ZTM= =-Ey/Hx = Ƞ βm/k. For ZTEM, m=0 ZTM=ZTEM= Ƞ. What in slide 13 and 49 are consistent, but not consistent with what in slide 15. How to understand that? Hope this is clear. Thanks
That textbook for this class is Sadiku. www.amazon.com/Elements-Electromagnetics-Electrical-Computer-Engineering/dp/0190698616/ref=sr_1_3?dchild=1&keywords=sadiku&qid=1616419496&s=books&sr=1-3
@@empossible1577 Thank you very much. Unfortunately, I'll have to pay more than half of it's amount extra for shipping to my country. I'll see if this is available in my college Library
Excellent lecture. Very clear. Thank you.
Heartiest thanks for the lucid explanation i've ever found. I've a request plz make video content on Circular Waveguide also.
Ah yes, Bessel and Hankel functions. Learn those and circular waveguides are pretty simple. Circular waveguides is on my radar for later.
A course on Antena Theory makes this RUclips channel a complete University in microwave and photonic engineering.
We are working on one here:
empossible.net/emp4305_5303/
@@empossible1577 Great. No need to take 7:00 AM in-person courses anymore :))))
where can i download your presentation?
I recommend using the course website as your main portal to the videos. You can download the notes, get links to the latest version of the videos, and access many other learning resources. Here is the link:
empossible.net/emp3302/
@@empossible1577 Thank you so much. It's really amazing. Finally found something useful.
1. For TEM mode, since phase constant = wave number, so isn't the speed going to be affected? And what do you mean by "an infinite medium"?
2. Do evanescent modes appear at the cut off frequency?
3. Why there's a minus sign in the expression of impedance (y-component of E-field & x-component of H-field)?
4. Effective refractive index is less than 1,so wave moves with speed higher than that of light. How's it possible?
1. For TEM, speed is not affected. By infinite medium, I mean a plane wave propagating in a homogeneous medium that is of infinite extent.
2. It makes more sense to talk about evanescent fields in the cladding of a dielectric waveguide. When a mode is cutoff, in fact, the mode still exists, but decays quickly as it propagates.
3. A negative sign may appear for backward waves since the H field has the opposite direction as it did for a forward wave.
4. Excellent question! See Lecture 5e.
Why the surface current in slide 14 is 1/2 for h1 sheet
The surface current is not 1/2 or even 1/2 of K. The surface current is K. The 1/2 means the magnetic field above an infinite current sheet is 1/2 of K cross n. If you would like to see this equation derived, checkout Lecture 5c here:
empossible.net/emp3302/
Dear Professor, thanks for the video. It helps a lot.
Question regarding impedance:
In page 15, you used transmission line definition to calculate ZTEM=Vo/I=Ƞ d/w.
In page 13, you got Ey and Hx, essentially you could you Z=-Ey/Hx to caculate ZTEM= Ƞ.
In page 25, you gave ZTM= =-Ey/Hx = Ƞ βm/k. For ZTEM, m=0 ZTM=ZTEM= Ƞ.
What in page 13 and 25 are consistent, but not consistent with what in page 15.
How to understand that?
The characteristic impedance is not usually E/H. Normally, you would do a line integral of the electric field to calculate voltage across the lines, do another line integral of the magnetic field to calculate the current through the line, then Z=V/I.
@@empossible1577 Thanks for your quick reply. But sorry, I don't get it yet. Also I found I made some small mistakes when I presented the question which may have confused you. Let me re-present the question as below:
Question regarding impedance:
In slide 15 video time 13:15, you used transmission line definition to calculate ZTEM=Vo/I=Ƞ d/w.
In slide 13 video time 9:53, you got Ey and Hx, essentially you could you Z=-Ey/Hx to caculate ZTEM= Ƞ.
In slide 49 video time 47:40, you did give ZTM= =-Ey/Hx = Ƞ βm/k. For ZTEM, m=0 ZTM=ZTEM= Ƞ.
What in slide 13 and 49 are consistent, but not consistent with what in slide 15.
How to understand that?
Hope this is clear.
Thanks
Can you tell me which book are you referring?
That textbook for this class is Sadiku.
www.amazon.com/Elements-Electromagnetics-Electrical-Computer-Engineering/dp/0190698616/ref=sr_1_3?dchild=1&keywords=sadiku&qid=1616419496&s=books&sr=1-3
@@empossible1577 Thank you very much. Unfortunately, I'll have to pay more than half of it's amount extra for shipping to my country. I'll see if this is available in my college Library
@@gohan12991 I tried to design my notes to they are self-contained. You should not need the textbook for anything in this course.
@@empossible1577 Thank you☺️☺️
Excuse me, the pdf of this lecture on your website is 404 not found😣
Sorry! Fixed!