Fixture Simulation

The fixture simulation function enables you to emulate the measurement conditions other than those of the real setup. The following conditions can be simulated:

- - Port Z conversion;
  - De-embedding;
  - Embedding.

Before starting the fixture simulation, first activate the channel. The simulation function will affect all the traces of the channel.

		To open the fixture simulation menu, use the following softkeys:
Note		The Fixture Simulator softkey label indicates the following:

Port Z Conversion

Port Z conversion is a function of transformation of the S-parameters measured during port wave impedance change simulation (See Figure 77).

Note		The value of the test port impedance is defined in the process of calibration. It is determined by the characteristic impedance of the calibration kit and the value is entered by the user as described in section 5.2.12.

Figure 77 Port Z conversion

		To enable/disable the port impedance conversion function, toggle Port Z Conversion softkey.
		To enter the value of the simulated impedance of Port 1, use Port 1 Z0 softkey.
		To enter the value of the simulated impedance of Port 2, use Port 2 Z0 softkey.

De-embedding

De-embedding is a function of the S-parameter transformation by removing of some circuit effect from the measurement results.

The circuit being removed should be defined in the data file containing S-parameters of this circuit. The circuit should be described as a 2-port in Touchstone file (extension .s2p), which contains the S-parameter table: S₁₁, S₂₁, S₁₂, S₂₂ for a number of frequencies.

The de-embedding function allows to mathematically exclude from the measurement results the effect of the fixture circuit existing between the calibration plane and the DUT in the real network. The fixture is used for the DUTs, which cannot be directly connected to the test ports.

The de-embedding function shifts the calibration plane closer to the DUT, so as if the calibration has been executed of the network with this circuit removed (See Figure 78).

Figure 78 De-embedding

		To enable/disable the de-embedding function for Port 1, use the following softkeys:
		To enable/disable the de-embedding function for Port 2, use the following softkeys:
Note		If S-parameters file is not specified, the softkey of the function activation will be grayed out.

Embedding

Embedding is a function of the S-parameter transformation by integration of some virtual circuit into the real network (See Figure 79). The embedding function is an inverted de-embedding function.

The circuit being integrated should be defined in the data file containing S-parameters of this circuit. The circuit should be described as a 2-port in Touchstone file (extension .s2p), which contains the S-parameter table: S₁₁, S₂₁, S₁₂, S₂₂ for a number of frequencies.

The embedding function allows to mathematically simulate the DUT parameters after adding of the fixture circuits.

Figure 79 Embedding

		To enable/disable the embedding function for Port 1, use the following softkeys:
		To enable/disable the embedding function for Port 2, use the following softkeys:
Note		If S-parameters file is not specified, the softkey of the function activation will be grayed out.