11-30-2015, 06:05 PM
(11-30-2015, 05:57 PM)mikikg Wrote: Heh, to sa RF zna biti vrlo zanimljivo ...
PCB iz AN lici da je u redu iz vise razloga.
Moguce je i tako vezati chip antenu ali uraditi bas kako su predlozili za sva 4 sloja, sa sve viama kako su rasporedjene oko antene i ostalih RF vodova.
Quote:That`s the beauty of high frequency design. You cannot look at the feed as a DC signal going straight to ground!
At 2.4 GHz the feed line is an inductor connected to ground (used for matching) along with a feed to the λ/2 monopole chip antenna. This ``free`` shunt inductor along with the antenna match components and of course the ground plane cutouts all play a role in determining the resonance of the chip antenna. Without being on resonance there will be significant radiated power loss.
An RF network analyzer with the final product assembly in free space should be used to select the antenna match components for targeting the resonance frequency and minimizing transmission line return loss.
https://e2e.ti.com/support/wireless_conn...8/t/363369
Miki,
hvala puno. Znao sam koga treba da pitam. Ja nikada nisam radio sa RF-om. Koristio sam CC3000 WiFi modul, ali kod njega je stvar skroz drugacija, pa me je ova prica skroz zbunila. Znao sam sve ove price vezano za karakteristicne vodove, ali reko GND je GND, pa cak i kod RF.
Hvala jos jedom Miki.