Synthesizer ADF4360-1: output impedance

I have a question regarding the output impedance of pins RFout.A and RFout.B. There is a figure 22 of the matching network in the datasheet of ADF4360-1, which "provides an excellent match to 50 Ω over the operating range" [datasheet]. If I take the this schematic and its values assuming load impedance 50ohm, then acc. the calculation the impedance of RF.out shall be ~ 50Ohm-j30Ohm. It leads to 70Ohm in parallel with 0.6pF as a model of single RF output pin. Thus the balanced impedance is build 140ohm & 0.3pF. But the balun is calculated with 50ohm balanced impedance on the fig. 23. And my question: what is correct balanced impedance? 50? 140? Or any other?