ADL5561 OIP3 vs Pout

Question

In the specification section for 140Mhz OIP3 is +39dBm for AV = 15.5 dB, RL = 200 Ω, VOUT = 2 V p-p composite (2 MHz spacing), but figure 13 shows another results. Why it is so ? 
 In my point of view 2 V p-p composite (RL=200Ohm diff or not ?) = 4dBm per tone ? And what the difference between 2 V p-p composite and 2 V p-p envelope?

rachana.kaza@analog.com · Accepted Answer

Hi, 
 For the ADL5561 and similar parts, because they are specified with a 200-ohm load, the dBm specifications are with reference to this impedance and not 50-ohms. 
 
 Yes, composite is the same as envelope. So 2Vpp composite is 1Vpp/tone for a two-tone sinewave test 
 
 However, because the part is specified with a 200-ohm load, Pout(dBm)/TONE is calculated as 10*log10(0.5*0.5/2/ 200 /1m) = -2dBm 
 Note: OIP3 in dBm is also plotted with reference to a 200-ohm impedance

This does make the number for OIP3 in the specification table look a little conservative. 
 OIP3 = 39dBm 
 IMD3 = -96dBc 
 If the numbers above are correct, then OIP3 from IMD3 would be 
 -2dBm(200) + 96/2 = 46dBm(200) vs 39dBm specified in the specification table. 
 IMD3 = -96dBc looks reasonable from Figure 12, but I cannot figure out how 39dBm was arrived at. 
 
 Warm Regards, 
 Rachana)

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ADL5561 OIP3 vs Pout