What is the Antenna Slant Angle and What is its effect?

General "Science" forum - where you may ask questions about the science of propagation, as well as help answer the technical questions regarding propagation.

What is the Antenna Slant Angle and What is its effect?

Postby SoulMate » Mon Apr 11, 2005 4:01 pm

Sirs,
I would like to know more about Slant Angle? and What is its effect on Wave Propagation??

What is the difference between Slant Angle,Elevation Angle and azimuth angle??

Warm Regards
SoulMate
 

Critical Angle & Frequency

Postby hamman_4 » Tue Apr 19, 2005 9:04 pm

As the transmitting frequency increases the RF energy that passes thru the ionized layer also increases and thus the mult-hop or skip condition necessary for long distance communication is affected. The angle of incidence has a direct impact on the angle of reflection as it relates to this ionized surface in that if the critical angle at which the signal leaves the antenna is too high for a given frequency then it will once again merely pass thru this ionized level and again conditions for multi-hop communications is also diminished. The relationship between radiation angles, the frequency you are transmitting on, the proximity of the sun to the earth, and which part of the ionosphere that is ionized all are directly related to the ability to communicate long distances via skip conditions. Typically first thing in the morning these layers are at there lowest point of ionization while during the mid day we see the high peaks and expect to experience better long distance communications on the shorter wavelength HF bands. Someone can correct me or add to this if I have missed or interpreted this incorrectly.
hamman_4
 

Postby kf4hou » Tue May 24, 2005 6:14 pm

i am not sure on slant angle maybe like polorazation angle like with satellittes? Elevation angle is the RF take off angles from a antenna in relation to true horizon like in 5 degrees up from true horizon, Azimuth Angle is in Which direction where most RF is going in like in a beam say you are pointed South That would make your Azimuth Angle 180 Degrees and for a omni directional antenna you are using 360 degrees around with hopefully low takeoff angles
and for propagation into the different ionshphere regions. i like to think like skipping a flat stone across water thinking as water as being the ionazation area Certain angles(and also the criticial angle) would hit the water and Reflect off the water other angles would be to steep and enter the water. so certain Elevation angles and frequency for a given Ionzation Area could be to steep and pass through that area into space , but for lower frequencies steeper angles can be used which thus produces shorter hops, very low angles would produce very long hops but remeber everything is in some relation with something else.
i thought i would add my two cents worth hope it enhanced the other guy explantion sorry for spelling as well :)
kf4hou
 


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