Hello, in the following circuit shown bellow i have two type of inputs and the output supposed to be the harmonics of a differential signal between the nodes of the capacitor as shown bellow.
i tried to simulate a two tone 10G and 10.1G to indicate that we have two inputs but its not working ,as shown in the end bellow?
where did i go wrong? and how to extract the hamonics of a differential signal shown bellow?
Two problems that I can immediately spot:
So if i understand you corretly, if i have two input sources then in the HB i choose two tones
IN1=square wave f1=1/T=10.1Ghz
IN2=sinus f2=10 Ghz
so what fundamental do we choose in the HB simulation?
Your tones you specified above were the other way around - the square wave was 10GHz, and the sine wave was 10.1GHz. You should specify two tones on the hb form, with the square wave (since it's the most nonlinear) being tone 1.
There's no need (nor should you, because that would be bad) to specify the output frequency as a tone, because that arise from the 1*10.1GHz-1*10GHz (or 1*1GHz-1*10.1GHz). So it's a harmonic combination of first order tones of the two input tones.
You don't have a single fundamental in the HB simulation - you specify each tone and the number of harmonics to simulate of each, and the harmonic balance outputs the matrix of harmonic combinations up to the max harms of each tone.
I understand so one fundamental is 10Ghz and the other is 10.1Ghz and for each fundamental i choose 5 harmonics.
i need my OUTPUT to be the harmonics of a differential signal, but when i choose DIRECT PLOT , i can choose only one NET on the schematics as shown bellow.
How can i get it to show me a differential signal harmonic as shown bellow?
5 harmonics may not be enough for the square wave signal - you might be better off leaving that as auto (you can only use auto on the first tone). You need to use Direct Plot->Main Form and then you can pick differential signals.
It seems as if you really need some training. At the very least, I'd suggest you take a look at the workshops that are in the SPECTRE/MMSIM releases - there's a compressed tar file in <SPECTREinstDir>/tools/spectre/examples/SpectreRF_workshop/rfworkshop.tar.Z - if you unpack this in your workspace with "tar xvfz rfworkshop.tar.Z" you'll find there's a doc directory with PDFs explaining how to simulate and measure various things for LNAs, mixers, oscillators and PAs. There's also the SpectreRF Theory manual in the documentation. This is not a substitute for training, but it's a good start.