Continue to Site

Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

Polarization of magnetic loop antenna...

Status
Not open for further replies.

Externet

Advanced Member level 2
Advanced Member level 2
Joined
Jan 29, 2004
Messages
600
Helped
28
Reputation
58
Reaction score
30
Trophy points
1,308
Location
Mideast US
Activity points
5,980
Good day all.
A loop antenna for VHF and UHF reception of television over the air, should it be positioned as it would lay flat on the ground or as hung from a nail on the wall ? Which one is vertical, which is horizontal polarization, (not position !) which one is better for TV ?
Here is both:
Loop-Antenna.jpg


And the RF transmitting station should come from the viewer direction into the image/wall or from left or right on the second image below ?

standing.png


(Images borrowed from the web)
 

Rewording the question...

What is the polarization of the vertically oriented loop antennas below and which gets a stronger signal for the same TX tower ?

loops 2.jpg
 

Is your question about antenna pattern (maximum signal direction) or polarization?

As described in the link below, polarisation of a small loop in vertical configuration (as shown) depends on the feedpoint location:
"The polarization of the loop antenna will be vertically or horizontally polarized depending upon the feed position. The vertical polarization is given at the center of the vertical side while the horizontal polarization is given at the center of the horizontal side, depending upon the shape of the loop antenna."


Your last question seems to be about antenna pattern maximum: for the small loop, maximum signal is in the plane of its wires (your right picture) with nulls broadside to the wires. Polarisation as discussed above.

Note that "loop antenna" here refers to electrically small loops. The examples that you showed above are much to large for VHF/UHF operation.
 

...for the small loop, maximum signal is in the plane of its wires (your right picture)...
Thanks for responding. Got it, the right picture on post #2 positioned for higher signal directionality. But what if it is not a small loop. What changes if the loop is large ?

...the loop antenna will be vertically or horizontally polarized depending upon the feed position...
Thanks. For the loops pictured in post #2, if the feedpoint is at the bottom, where the mast ends against the loop, the polarization will be horizontal; is that correct for the large loop, for a small loop or both ?

more crap.jpg


What is the polarization for this loop below, and its directionality ?

2mlambdaloop2.jpg
 

Status
Not open for further replies.

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top