S2p file with just s11 and s22

I have the VNA measured results of S11 and S21 (in ASCII format) of the resonator. Can I edit it to form s2p file and use it for ADS simulation of oscillator? Will the absence of S12 and S22 in the file cause any problem?



When I tried the error showed up in ADS : "Error detected while trying to read the s2p file. Unable to read required data from the touchstone file. Please ensure that the file is ASCII and correctly formatted." How can I proceed?

You need complete S-parameters for simulation. Your resonator is reciprocal, so you have S12=S21. Also, if it is symmetrical, S11=S22. Add these entries to the file.