2.1 Defining the type of the structure

Having the QW-Modeller opened and a new project document created, we can proceed with defining the type of the structure. First of all, we need to specify if we will be dealing with typical three dimensional (3D) or maybe periodic three dimensional (3DP) structures. The structure type, called also the circuit type, is determined in the Circuit Settings dialogue available in the Model tab, under the Circuit push button. In case of our waveguide to coaxial line transition we will be analysing typical 3D circuit.

Circuit Type tab in Circuit Settings dialogue.

At this stage it is necessary to determine also the background medium for our structure. Since our structure is non-radiating and we are interested only in the fields inside it (it is a closed structure type of problem), we can set the background medium to metal and then draw only the inside of the structure. To set the background medium, we switch to Basic tab in the Circuit Settings dialogue and choose metal from the Background Medium combo box. Please note that there is a choice of only two possible background media, air and metal.

In the Frequency Range section we set the operating frequency range for the project from 15 GHz to 25 GHz and also the frequency step for postprocessings 0.05 GHz. We can now set the same frequency range for the excitation and for postprocessings calculations by pressing Set for Ports and Set for Postprocessings buttons respectively.

Basic tab in Circuit Settings dialogue.