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.
There are three sources of loss. One is the resistance of the conductors. This is usually many orders of magnitude less than the radiation resistance and so rarely is a problem.
The second is from radiating power at directions other than the intended one. If the sidelobes are 20 dB down compared to the main beam this only wastes 1% of the power.
The third is reflections from the antenna on the transmission line (SWR). The power goes back down the transmission line and is reflected from the source and goes back to the antenna. This makes the attenuation of the line for this component of power three times ( in dB ) attenuated by the transmission line attenuation.
I think antenna efficiency is very important for small antennas such as the ones on partable devices. Many researchs have been done for acculately estimating radiation efficiency.
Yes, in small antennas, the problem of the efficiency is a very critical problem. There're lot's of reference talking about the topic of efficiency,such as the one in the attachment.And in simulation tools, such as IE3D,you can read the radiation efficiency and antenna efficiency, but as I thought definition of the radiation efficiency and antenna efficiency in IE3D is different from the definition in text book.The difference is in the second attachment.
This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
By continuing to use this site, you are consenting to our use of cookies.
can somebody tell me? thanks!