rfmems
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As known,in a diff. LC VCO, the oscillation voltage amplitude V=Z(f)*i, Z(f)is the loaded tank impedance. With PSS simulation, we have the output voltage, with the current i known, it is easy to calcultate the loaded impedance at different harmonics. Question is how to get this current, where should I probe or how should I calculator? I have tried the current on the transistor drain, but the result seems strange. It seems that it gives only the impedance of the LC tank, and the transistor loading and changing of Idc or Vdc doesnot effect Req at all.
Somebody help me out, thanks.
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