Thanks for responding........I apologize in advance with all the trivial and meticulous questions. I hope you can understand what Im trying to ask.
Originally Posted by DeboraHarry:
"1) It is normal to talk of "azimuth" and "elevation" in antennas. If the antenna is vertically polarized, then the E-plane diagram shows you how the antenna behave with elevation. The H plane diagram shows you how it behaves along the horizon (aziimuth).
2) If the antenna is horizontally polarised, then these patterns are reversed."
so elevation corresponds to E field, that are vertical. So you are looking at antenna radiated energy in a plane that is is perpendicular to the earth?
so azimuth corresponds to H field, that are horizontal. So you are looking at antenna radiated energy in a plane that is parallel to the earth?
So the plots should not be referred to as vertical or horizontal but instead only the physical position of the antenna should be referred to as vertical or horizontal?
Or just think about vertical and horizontal in terms of the E and H fields?
Please, robismyname, think back in time when radio was first being invented and the first antennas were very long or tall structures. We will think in terms of tall and not 'long' for this discussion.
Think of the common commercial AM Broadcast Band antenna (530 kHz thru 1700 kHz), which for 1 MHz frequency the 1/4 Lambda length is about 250 feet or 76 meters, straight up. We will ignore 'ground radials'.
The orientation of this antenna's Electric field is vertical, matching the vertical orientation of the 1/4 wave element which possesses a voltage gradient along its vertical length, low voltage at the bottom and high voltage at the top. Their is also an associated magnetic field, high at the bottom and low at the top, but I will ignore it for the moment.
Now, we refer to what DeboraHarry posted:
"1) It is normal to talk of "azimuth" and "elevation" in antennas. "
. Azimuth - relates (for our case with the vertical AM Broadcast antenna) to compass bearing.
. Elevation - is the angle 'up' (or down as well, if the antenna were in free space we could plot this part of the pattern too)
"2) If the antenna is vertically polarized, then the E-plane diagram shows you how the antenna behave with elevation. "
. At the horizon, then, at zero degrees elevation the 1/4 wave vert has its strongest response or signal
. At straight up the 1/4 wave vert has very little (theoretically zero) response or signal.
"3) The H plane diagram shows you how it behaves along the horizon (aziimuth). "
. At the horizon are where the people who hear your broadcast reside.
. Looking at all compass 'bearing' (Azimuth) angles gives you the H-plane response. It will be equal in all directions for our 1/4 wave vert.
"4) If the antenna is horizontally polarised, then these patterns are reversed."
Yup.
RF_Jim