Hello everyone,

I am currently working on a CST Studio Suite project (Statics/Low frequency → Sensors → Capacitive Sensors, student license).
I have created a 3D geometry, along with the 3D printed circuit board. The RLC components are implemented via lumped elements, but the PCB also contains an amplifier, so in order to perform a low-frequency analysis of the PCB, I need to import the behavioral model of the amplifier and connect it to the copper geometry (it has eight round faces, which represent amplifier pads - see the picture 1.AmplifierPads_3Dmodel attached). The gray faces, on which I apply voltage or which represent an input/output of the amplifier, are defined as PEC (Perfect electric conductor), whereas the electric potential is defined using the Electric Potential option from the Simulation tab. Each potential value can be either Fixed or a Floating potential (i.e., not set, depending on the rest of the circuit).

I have managed to import the behavioral model of the amplifier via SPICE block in the Schematic window, but unfortunately, my model block in Schematic recognizes only outputs that belong to the geometry faces that are marked with fixed potential (see the picture 2.Model_and_SPICE_block attached). Specifically, I have four PCB faces on which I apply fixed potential (VCC, VDD, GND and Potential) and two faces which I marked with floating potential (inputs of the amplifier), but in the Schematic window, my model gives me only 4 outputs - all 4 of them belonging to the fixed potential faces. Naturally, I would like the input of the amplifier to operate on a floating potential.

Is there any way to achieve that my 3D model in 3D geometry window gives me floating potential faces as the outputs in the Schematic window, so that I could connect it to the input of the amplifier (see the third picture 3.Desired attached)?

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