Ok, I can assume a parallel RC for the load right now with reasonable values
So we can view the circuit like : atenna->matching->Load
I am confused which to start with ? matching or antenna ?
I think i have to design the antenna then caculate its impedence and match the load to what i have calculated, right ?
If so, which parameters and equations i need to consider while designing the antenna?
My initial guess, the antenna can be modeled with RLC resonant circuit (series or parallel) so i should design for a certain L achieving the required coupling and this is L, then caculate the ohmic losses and this is R (perhaps i might add another R to get a certain impedence, e.g 50ohm), distributed C should also be caculated hence i can add another C to tune the antenna to 13.56M
I think this is what i am supposed to do, but i do not know how to practically achieve this? the first step is the big problem ? how to design for a certain L?
there are a lot of things here like geometry, number of turns, dimensions, etc
which drives me crazy !
So what do you think i should do ?
By the way, i thinks ADS can help with this, so is there any example of designing a microstrip antenna with ADS ?
can you provide me with URL to any of those RFID vendors that provide examples?