See attached scanned pages of page 118(left side) and page 125(right side) of Antenna Theory by Balanis.
On the left side, it is just some basic EM where
[tex]\nabla\times \vec E=-\frac{\partial \vec B}{\partial t}\;\Rightarrow\;\vec E=-\nabla V-\frac{\partial \vec A}{\partial t}[/tex]
Then to Lorentz thingy ##\nabla\cdot \vec A=-\mu\epsilon \frac{\partial V}{\partial t}##.
And so on......
The only thing different is it is in time harmonic form where ##\frac{\partial}{\partial t}\rightarrow\;j\omega##.
Now going to the right side. I underlined the sentence that I have no idea where that comes from!! What is ##\frac {1}{r^n}=0## where n=,2,3,4.....
Please explain what is that. This supposed to be very basic thing that
[tex]\vec B=\nabla\times\vec A[/tex]
Then for far field where it is assumed plane wave,##\vec E=\eta\hat R \times \vec H##
This is a very basic knowledge of finding E and H from A. Where is all the what looks like numerical stuff come from?
Please help.
Thanks
On the left side, it is just some basic EM where
[tex]\nabla\times \vec E=-\frac{\partial \vec B}{\partial t}\;\Rightarrow\;\vec E=-\nabla V-\frac{\partial \vec A}{\partial t}[/tex]
Then to Lorentz thingy ##\nabla\cdot \vec A=-\mu\epsilon \frac{\partial V}{\partial t}##.
And so on......
The only thing different is it is in time harmonic form where ##\frac{\partial}{\partial t}\rightarrow\;j\omega##.
Now going to the right side. I underlined the sentence that I have no idea where that comes from!! What is ##\frac {1}{r^n}=0## where n=,2,3,4.....
Please explain what is that. This supposed to be very basic thing that
[tex]\vec B=\nabla\times\vec A[/tex]
Then for far field where it is assumed plane wave,##\vec E=\eta\hat R \times \vec H##
This is a very basic knowledge of finding E and H from A. Where is all the what looks like numerical stuff come from?
Please help.
Thanks
