What makes antenna to radiate

  • Thread starter shankar
  • Start date
  • #1
17
1
what makes antenna to radiate,the basic principle...

:smile:
 

Answers and Replies

  • #2
chroot
Staff Emeritus
Science Advisor
Gold Member
10,239
39
You pass radio-frequency alternating currents through the antenna. The electrons in the antenna get jostled back and forth. Jostling electrons create jostling electromagnetic fields. Jostling electromagnetic fields are what we call "radio waves."

- Warren
 
  • #3
Integral
Staff Emeritus
Science Advisor
Gold Member
7,212
56
Currents induced in the antenna by the transimtter, produce a Electro magnetic field. This is all coverd by Maxwells equations. Due a web search on that key word for more information.
 
  • #4
17
1
the alternating current produce fiels...then what about the induction principle....where electric field produce only magnetic field no radio waves???
[?]
 
  • #5
chroot
Staff Emeritus
Science Advisor
Gold Member
10,239
39
Originally posted by shankar
the alternating current produce fiels...then what about the induction principle....where electric field produce only magnetic field no radio waves???
[?]
Changing electric fields create magnetic fields. Changing magnetic fields create electric fields. You cannot jostle an electron around without producing SOME radiation.

- Warren
 
  • #6
256
0
Originally posted by chroot
You pass radio-frequency alternating currents through the antenna. The electrons in the antenna get jostled back and forth. Jostling electrons create jostling electromagnetic fields. Jostling electromagnetic fields are what we call "radio waves."

- Warren
To elaborate , electrons jostle against ions which are held in a fixed position in the crystal lattice of the conductor , causing the ions to vibrate and produce electric fields.
 
  • #7
17
1
ya its true E&M are there but at what condition they the element radiates field?
 
  • #8
chroot
Staff Emeritus
Science Advisor
Gold Member
10,239
39
Originally posted by shankar
ya its true E&M are there but at what condition they the element radiates field?
What?

- Warren
 
  • #9
Integral
Staff Emeritus
Science Advisor
Gold Member
7,212
56
Originally posted by McQueen
To elaborate , electrons jostle against ions which are held in a fixed position in the crystal lattice of the conductor , causing the ions to vibrate and produce electric fields.

Ionic motion is not needed, electron motion alone will do the trick. In fact any ion vibration will probably be in the infra red energy region.
 

Related Threads on What makes antenna to radiate

Replies
1
Views
3K
  • Last Post
2
Replies
25
Views
18K
  • Last Post
Replies
5
Views
1K
  • Last Post
Replies
5
Views
2K
  • Last Post
Replies
4
Views
819
  • Last Post
Replies
9
Views
2K
  • Last Post
Replies
11
Views
3K
Replies
2
Views
727
Replies
26
Views
3K
Replies
1
Views
10K
Top