slienteyes
Junior Member level 2
is it possible to measure a negative resistance
How to measure the negative resistance of CB topology of VCO by simulation of ADS?
I simulate for oscillation condition for my common base topology VCO in ADS with osctest. I don't know what the zo in osctest means. normally zo in osctest should be 1.1ohms. why? actually osctest is to get the S11, but why should say S11 from osctest is loopgain? Why S11 so called loop gain in nyquist plot should have magnitude larger than 1 and phase around 0 so as to have the potential to oscillate?
How can I get the negative resistance value from this ADS simulation?
My VCO schematic:
My simulation results:
How to measure the negative resistance of CB topology of VCO by simulation of ADS?
I simulate for oscillation condition for my common base topology VCO in ADS with osctest. I don't know what the zo in osctest means. normally zo in osctest should be 1.1ohms. why? actually osctest is to get the S11, but why should say S11 from osctest is loopgain? Why S11 so called loop gain in nyquist plot should have magnitude larger than 1 and phase around 0 so as to have the potential to oscillate?
How can I get the negative resistance value from this ADS simulation?
My VCO schematic:
My simulation results: