Regarding Harmonic Balance Convergence
The HB simulation engines in ADS are extremely robust, but sometimes switching mode designs like this can push convergence because there are so many harmonics in the signal.
There are a few things that can help convergence if you run into problems.
- Try changing the order of the harmonic balance simulation (sometimes for switching modes, more harmonics are needed).
- Try sweeping the input power over a range around the point you are interested in, and try adding more points to your sweep.
- Double click on the harmonic balance controller and go tothe solver tab -- try the Krylov solver -- and if that doesn't work, under advanced Krylov parameters, try setting the preconditioner to SCP.
- In the options controller, try setting the convergence check to relaxed.
- Double click on the harmonic balance controller, and in the initial guess tab, try turning on transient assisted or harmonic balance assisted harmonic balance.
- Try using the NdSet block to specify an initial guess for known DC levels at various nodes.
- Finally, try doing an S-parameter simulation -- sometimes convergence problems mean you have an unstable region and / or there is a problem with your PA circuit.
