Trying to figure an antenna for the Si4012 RF chip. Page 26 of https://www.silabs.com/documents/public/application-notes/AN639.pdf talks about feeding the two sides of the loop antenna through two pull-up inductors (LP and LM) which it fails to provide any values for.
I have read here that I should
Select a sufficiently high inductance value. (Z = 2 * pi * f * L) Select an impedance (Z) that is much larger than the load resistance.
This usually translates into "make it tenfold"
In my design, |Z_load| is somewhere between 500 and 600 ohm (PA and adapted differential antenna). Wouldn't it be required to pick an inductor having its impedance in the 5k - 6k ohm interval in order to actually be effective at blocking the fundamental + first few armonics ? -
- Meaning 2.2 uH with a SRF of more than 1736 MHz in order to cut out everything to and including the 3rd armonic. The trouble is I am unable to find on the market such a large inductor at that kind of SRF. They usually go to 100+ MHz SRF at 2.2 uH. Perhaps I am miscalculating something ?