Is 0.6 voltage drop od D1 enough to comepnsating forward voltage drop on D2 ?
I don't think so because there are another two resistors R1 and R2 which produce voltage drop ?
That circuit looks like it is designed for a small RF signal. D1 and D2 should be matched and thermally linked for best performance.
If you want a "perfect diode" for relatively low frequency signals then the OpAmp rectifier works well: **broken link removed**