In the datasheet, IM3 (dBc) graphs are provided against RF input power (dBm) for internal AGC mode. My questions are:
1) IM3 unit is dBc in datasheet. Is this relative to input carrier or output carrier?
2) I actually want to deduce IIP3 or OIP3 for the IC in internal AGC mode. KIndly help me out
The IM3 is dBc with reference to the IF output tones. The AGC is set to keep the IF output fixed at -9 dBm per tone. The input power is swept in 5 dB steps (refer to x-axis) and the IM3 is measured at IF output. The RF input power represents the combined power of the 2-tones. You can use -9 dBm per tone at IF output to calculate the IP3.