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Design >> RF Design >> About matching of RF system
https://designers-guide.org/forum/YaBB.pl?num=1215710212

Message started by Julian18 on Jul 10^th, 2008, 10:16am

Title: About matching of RF system
Post by Julian18 on Jul 10^th, 2008, 10:16am

Hi, there
As we all know LNA should have a specific input impedance for matching, but mixer and all other block dont have that specification(in RFIC design). I wander if I can explain it in the following way:
if the signal is transmitted in the form of wave (e.g. a LC network.) and the wavelength is much smaller than the transmitting path, you should take the reflection into account. on the other hand, if the signal is transmitted in the form of diffusion (e.g. a RC network.) or even if the signal is transmitted in the form of wave, the wavelength is large compare to the transimitting path, the voltage is more relevant.
I'm not sure if I am right or wrong. Any comment on this is welcome.

Best Regards

Julian

Title: Re: About matching of RF system
Post by Stefan on Jul 10^th, 2008, 1:50pm

You're right. That's the problem why "on-chip" machting of e.g. mixers is so difficult to discuss. Anyway, matching of Antenna to the LNA is important to get the most energy out of the air-interface.

On-Chip it's more important to discuss driving capability of preceeding stages.

Don't forget that all illusions of "waves" is mainly a model to explain nature's phenomenoms :)