I am currently using ADS 2011 to design a RF Amplifier.
Steps:
1. Do Momentum simulation of the circuit.
2. Drag the simulated model to schematic platform.
3. Add other lumped elements(RF choke, DC block and resistors.) 4. Choose EM model for the circuit. I got issue when I was doing this step. Only did I choose layout, I could finish the simulation in Schematic platform.
So, is there any problem when I am using this method to design amplifier in ADS? Or, how can I design a amplifier in ADS via momentum simulation?
Momentum simulation is for passive devices which in your case is for your matching circuit. Basically as long as you add your active device in step 3, there is no problem with steps mentioned above.
Power amplifiers are highly nonlinear blocks; In addition to S-parameter simulation, consider some other simulations like HB.
So, if I add BJT component to my momentum simulated layout, the schematic simulation can not be done properly? And, the reason is that momentum simulation is not for active devices?
So, if I add BJT component to my momentum simulated layout, the schematic simulation can not be done properly? And, the reason is that momentum simulation is not for active devices?
That's right; Momentum simulation is only for passive devices. You have to simulate your passive circuit in Momentum and then create a symbol (layout look alike is better to understand what you are doing) and choose EM model for it. The rest of simulation with added active and power supplies will be carried on with simulations in the schematic view.
So after I did the momentum simulation, I could connect the layout model (EM model) and active components, like BJT, and then simulate the performance of the whole circuit in the schematic view?
However, when I was trying to do the simulation in the schematic view, I could not get the expected performance. Is it because the BJT kit is non-linear component; therefore, it can not be simulated when it connect with a EM model of momentum simulation result?
So after I did the momentum simulation, I could connect the layout model (EM model) and active components, like BJT, and then simulate the performance of the whole circuit in the schematic view?
However, when I was trying to do the simulation in the schematic view, I could not get the expected performance. Is it because the BJT kit is non-linear component; therefore, it can not be simulated when it connect with a EM model of momentum simulation result?
Simulating a schematic with a connected S-parameter block (EM model in this case) to a nonlinear model of BJT should not be a problem. I did this kind os simulation about 4 years ago and as far as I remember everything was OK.
Did you check the DC behavior of your EM model? does it handle DC voltages and currents as you have in your mind?
I could not get the expected performance. Is it because the BJT kit is non-linear component; therefore, it can not be simulated when it connect with a EM model of momentum simulation result?
Don't choose View as 'Layout', choose em-view for Momentum simulation. Also if you are using latest version of ADS then during EM-view generation you can identify passive and active models, so there will not be any need to replace active component with Pins in mometum simulation and then again replace this with active component in shematic.