You build the mixer schematics and you add the harmonic balance icon.
Make sure you add in schematics any kind of AC source, even AC with DC component in it would do fine I guess.
ADS is smart not to assume a pure harmonics (Fourier series says that theoretically) but takes a better step by repetitively having to conjugate gradient sorting few things.
Since everybody adding notes, I am attaching one myself.
any special things I should note for SOM HB simulations?
Actually I have tried and reflected the problem I faced in another tread... I can't see my RF spectra when doing the sim... Needless to say, my IF spectra is nowhere to be found.
First I simulated a the DRO with a 50ohm R on the gate end of the FET. HB works fine, I got fundamental ~10dBm. Next I replaced the 50ohm R with a 50ohm (-20dBm) RF source. Now the HB results are not quite what I expected... There should not be any impedence mismatch...
hi gecky,
look man, there might be several reasons 4 ur prob (as far as i know) ,
- check ur power source & make sure it s a (single tone source)
- try 2 adjust the power level, start 4 example from 0dBm till 10dBm or 20
- try 2 adjust the order of the HB controller
another suggestion, why not 2 use LSSP controller ? it also based on HB !
I used a single tone source. Do you mean that the RF power may need to be varied till I see the RF being mixed in? And that I can use a LSSP sim to sweep this source pwr level?
My HB order has been set to 8, seems to be the optimum for my DRO. I don't think changing to higher order will affect the IF spectra much since it is way way below the expected.
try 2 use an odd harmonic balance order (better 3 or 5) and a frequency sweep 4 the LO frequency band, keep the power level of ur source constant & investigate it like that !