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Summary
| Description |
English: Three dimensional far field radiation pattern of a three-eighths (0.625) wavelength vertical monopole antenna over a perfectly conducting infinite ground plane. This is a common antenna because at this length a monopole radiates the maximum power in horizontal directions. Monopole antennas longer than this are seldom used because at greater lengths the power radiated horizontally decreases rapidly and more power is radiated into the sky in the high angle lobes. The pattern has two lobes; a main donut-shaped lobe in horizontal directions and a smaller conical lobe with maximum at 60° into the sky. The graph is axially symmetric about the antenna's vertical axis, and is resting on the ground plane. The origin of the coordinates is where the axis intersects the ground plane. The distance of the surface from the origin in any direction is proportional to the magnitude of the electric field (signal strength) radiated in that direction. From dipole equation in Balanis, 2005, Antenna Theory 3rd Ed. p.172, eq. 4-62a |
| Date | |
| Source | Own work |
| Author | Chetvorno |
Generated by GNU Octave program:
# mpole3d.m
# length = length of element in wavelengths
#--------------------------------------------
function mpole3d (length)
thetasamples = 100; #theta resolution
phisamples = 100; #phi resolution
colormap bone; #colorscheme
[theta,phi] = meshgrid(linspace(0,pi./2,thetasamples), linspace(0,2.*pi,phisamples)); #creates grid
kl = 2 .* pi .* length; #length in radians
r = (cos(kl .* cos(theta)) - cos(kl)) ./ sin(theta); #Directivity equation
r = r .* sign(r); #fix - make signal strength positive
x = r.*sin(theta).*cos(phi); #maps grid onto radiation surface
y = r.*sin(theta).*sin(phi);
z = r.*cos(theta);
surfl(x,y,z); #creates a smooth solid surface with specular reflections
shading interp #continuous shading hides wireframe
axis("equal", "tight", "off"); #same scale factor, no padding, turn off axes
view(-37,15); #Lowered viewpoint so can see structure better
xlim("tight");
ylim("tight");
zlim("tight");
print -dpng mpole3dpattern.png; #save image in file
endfunction
Licensing
I, the copyright holder of this work, hereby publish it under the following license:
 
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This file is made available under the Creative Commons CC0 1.0 Universal Public Domain Dedication. |
| The person who associated a work with this deed has dedicated the work to the public domain by waiving all of their rights to the work worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law. You can copy, modify, distribute and perform the work, even for commercial purposes, all without asking permission.
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File history
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| Date/Time | Thumbnail | Dimensions | User | Comment | |
|---|---|---|---|---|---|
| current | 06:11, 7 December 2024 | | 490 × 470 (28 KB) | Chetvorno | Uploaded own work with UploadWizard |
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