AnsweredAssumed Answered

Netlist order could affect Phase Noise in ADS2003A

Question asked by TNAKA on Jun 17, 2003
Latest reply on Jun 24, 2003 by TNAKA
It seems that order of transistor and OscPort in netlist
could affect a phase noise(pnmx) result.
In my case, phase noise results are different between the following two cases.

(1) Case-1
OscPort:I6 net044 net14 Z=1.1 NumOctaves=2 Steps=10 FundIndex=1 Harm=1
npnStd:Q0 net20 net044 net37 0

(2) Case-2
npnStd:Q0 net20 net044 net37 0
OscPort:I6 net044 net14 Z=1.1 NumOctaves=2 Steps=10 FundIndex=1 Harm=1


(1) gives about 2dB larger result than (2)
regarding pnmx in very small offset frequency region(less than 5Hz).

Why does order in netlist affect an phase noise(pnmx) result ?

It could cause a confusion for user who use both native ADS schematic and RFDE,
since native ADS and RFDE don't always give same order in netlist.

[Note] pnfm is not affected by order in netlist.  

Outcomes