# What makes antenna to radiate

what makes antenna to radiate,the basic principle...

chroot
Staff Emeritus
Gold Member
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

Integral
Staff Emeritus
Gold Member
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.

the alternating current produce fiels...then what about the induction principle....where electric field produce only magnetic field no radio waves???
[?]

chroot
Staff Emeritus
Gold Member
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

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.

ya its true E&M are there but at what condition they the element radiates field?

chroot
Staff Emeritus
Gold Member
Originally posted by shankar
ya its true E&M are there but at what condition they the element radiates field?
What?

- Warren

Integral
Staff Emeritus