RIPPLE on radiation pattern due to SURFACE WAVE
can anybody explain how the ripple is, exactly?
any reference explaining it?
any figure to show that?
Hello Hamid.. !
Can you explain exactly what you said about the 'antenna pattern' ? - is it the far field radiation pattern ?
I think you mean the near filed radiation pattern - which depends on the geomtrical structure of the given antenna.
But surface plane wave exists at the far field of the antenna (when they far away in several wavelengths).
Thanx !
hi
i guess, farfield
in an IEEE transaction by DAN SIEVENPIPER titled HIGH IMPEDANCE EM SURFACE USING EBG he mentions the sentence but without any reference: surface waves if scattered, caues distortion in pattern in form of ripple.
DISTORTION AND RIPPLE seem ambiguous to me.
ok?
Hello !
I think he means by Ripples that the far field doesn't have a smoth curve of charactersitic and, due to scatterd surface waves, this far field pattern has a noisy (distorted) pattern.
Thinks of it as an unwanted noise reflected from the antenna as shown at far field pattern image attached.
If you have something else to show me - you're more then welcome.
Itzik !
P.S.
the far field pattern was taken from 3rd edition of Antenna Thoery of Balanis C.
(Last chapter of measurements antenna's paramters)