Getting Optimization Error using ADS tool

[hari_preetha]

I am getting error while doing optimization of LPF circuit using ADS. Some can tell how to sort this problem. I have screen shot of Error and Schematic.

 

[BigBoss]

Values should be defined for optimization, but you have defined for tuning.
They should have been L1{o}.

 

[hari_preetha]

It seems to be everything correct, but it is showing errors. Someone can suggest where I have to go and what values should I change to eliminate errors?

 

[BradtheRad]

Try installing a low-ohm resistor inline with each capacitor. Without it the simulator has trouble calculating an RC time constant.

Furthermore there are inductors adjacent. LC combinations with no resistance can have unrealistically high Q which leads to unrealistic performance.

 

[RealAEL]

As Big Boss mentioned previously you are using the Tuning option in the Simulation Variables Dialog. You should have all these setting in the Optimization Tab (the second tab) to get optimization to work.

 

[hari_preetha]

As Big Boss mentioned previously you are using the Tuning option in the Simulation Variables Dialog. You should have all these setting in the Optimization Tab (the second tab) to get optimization to work.

I am not understanding where I have to go and make changes. If you show making changes through screen shots, I can understand easily and follow it. I have attached screen shots for your reference. I have followed ADS cook book given example exactly. I am facing difficulty in obtaining desired results ( as shown in the ADS Cook Book).

--- Updated Nov 13, 2022 ---

As Big Boss mentioned previously you are using the Tuning option in the Simulation Variables Dialog. You should have all these setting in the Optimization Tab (the second tab) to get optimization to work.

I have done exactly as he said. I am not getting output. I have followed the steps exactly which has given in the ADS Cook Book Optimization example. If you show through screen shots what I have to do, I can understand easily and make changes in the my optimization example.

 

[RealAEL]

You initially reported that an error was generated when attempting to perform optimization for this design. I presume that now with better set-up for the optimization variables that this error is no longer the problem.

Now you simply say that "I am not getting output" but this is not helpful to diagnose what may or may not be happening. Do you get any different error messages now? Exactly what steps are you trying to perform and what response do you see? What are you expecting to see? You need to provide a better description of the current situation for anyone to be able to suggest solutions.

 

[BigBoss]

I think the variables cannot contain both Optimization and Tuning features.
Either Optimization OR Tuning should be valid.

 

[RealAEL]

I think the variables cannot contain both Optimization and Tuning features.
Either Optimization OR Tuning should be valid.

It is entirely appropriate to define multiple Tune/Opt/Stat/DOE Setup to a single parameter or variable. They are never all used at the same time, but each is active for the different types of simulation. So, ADS allows the user to enable all four concurrently, but the simulator only uses one at a time.

This appears in the netlist as:
R:R3 N__84 N__80 R=50 Ohm tune{ 25 Ohm to 75 Ohm by 5 Ohm } opt{ 25 Ohm to
100 Ohm } stat{ gauss +/- 2 % } doe{ 10 Ohm to 40 Ohm } Noise=yes

So that is not the problem, but I would certainly like to know from this member a better description of what is happening.

 

[hari_preetha]

So that is not the problem, but I would certainly like to know from this member a better description of what is happening.

I have attached ADS execution file. Have a look on the optimization ADS file.

 

[RealAEL]

Looking at the first design, Optimization_L_C_R, there are many items entered incorrectly and a couple of these are blocking the simulation from working.

In the second design, Optimization_L_C_R_Modi, you appear to have 'fixed' most of these issues but there is still one remaining. In the Optimization Goal OptimGoal1 you have the Swept Variable set as both "Freq" and "freq". ADS does not know what "Freq" is (ADS is case sensitive). Delete the "Freq" value and leave only the "freq" setting. The Optimization should now run.

 

[BigBoss]

-You didn't enter "Step" frequency value, so you have to do it. It should be-let's say- 1MHz to 500MHz by 1MHz.
Otherwise, the simulation will be very coars.
-"Freq" variable cannot be defined, instead you should use "freq" variable by default.
-Components' values should be "Standard" in Optimization field NOT "Name=Value"
-Check the variables and their limits in Simulation-->Simulation Variable Setup
Finally, pursuit ADS tutorial and application notes to learn ADS Correctly.