These devices are rather distributed and their behavior is similar to a microstrip port source. In other words, the active one-port requires a rectangle strip object as a host, while the active two-port requires two rectangle strip objects for its definition. You can choose one of the edges of the strip object for establishing the circuit port. In the case of a two-port device, you need two parallel and end-to-end aligned strip objects.
The circuit behavior of these devices is defined by a Netlist file. Their property dialog provides a text editor for simply writing the Netlist description of the device. You can also import an existing external Netlist file with a ".CIR" or ".TXT" file extensionusing the button labeled {{key|Load Netlist}}..
{{Note|[[RF.Spice A/D]] can generate a Netlist file corresponding to an existing circuit project. The Netlist file , which can then be save saved to a text file with a ".TXT" file extension. When importing such files to EM.Tempo, you need to change the file extension to ".CIR".}}
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<td> [[Image:ActiveOnePort.png|thumb|left|480px|EM.Tempo's active one-port device/circuit dialog.]] </td>
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<td> [[Image:ActiveTwoPort.png|thumb|left|720px|EM.Tempo's active two-port device/circuit dialog.]] </td>
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