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cbjewelz AntennaTheory.com Newbie
Joined: 28 Jul 2011 Posts: 1

Posted: Thu Jul 28, 2011 9:05 am Post subject: Gaussian Taper Radiation Pattern 


Hey guys, hopefully you can help me out on this topic. Sorry if I can mix up some terms, this is not my area of expertise:
I have an antenna with a 10 dB Gaussian taper (window function) and want to model the radiation pattern of this aperture in the far field, i.e. intensity vs theta. Is this straight forward? Does it matter what type of antenna I have if I am extremely far away (so it can be modeled as a point source)? Any help much appreciated. Thanks 

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Schubert Antenna Wizard
Joined: 08 Apr 2009 Posts: 161

Posted: Sun Jul 31, 2011 2:03 am Post subject: 


The radiation pattern is mathematically equivalent to the fourier transform of the current distribution.
This can be seen somewhat intuitively: very small antennas have broad radiation patterns (analogy: fourier transform of short impulse function is a broad constant in frequency) and the radiation of a very large antenna is highly directional (the fourier transform of a constant function is an impulse).
So, the Fourier Transform of a gaussian is a gaussian, then your radiation pattern should have a Gaussian shape. The tighter your current (i.e. the lower the sigma in the gaussian function, or spread of your current) the broader the pattern will be.
Here's more info if you want to learn Fourier Transforms:
http://www.thefouriertransform.com/ 

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