Once we have the entered the dimension for the substrate, we have to select its material property. Give a name to the brick shape "Substrate", and enter the Width(-W,W), Length(-L,L) and Height(h) as shown in the figure below. This will bring up a window that allows users to specify the dimension of the substrate. To create the RT Duriod substrate, select the brick shape tool and press ESC. Note: If the parameter list table is not visible, go to view menu at the top toolbar and tick on the parameter list. The dimensions calculated earlier and information obtained from the manufacturer is listed below.
"d" is the inset fed distance and g is the gap between the patch antenna and the microstrip feed line. Wf and Lf are the dimension of the microstrip line. It is just a dimension which is greater than the patch antenna and the dimension for ground plane has no significant operation on the antenna. There is also a general rule for the dimension of the ground plane but this is not followed here. In fact here the ground plane underneath the substrate has the same dimension as that of the substrate. The substrate can have other dimension greater than the patch antenna size. The substrate has twice the width and length of the patch antenna, that is, 2W and 2L. W and L are the width and length of the patch antenna. The antenna that will be designed is shown in Fig 1. Readers can visit the first part or the third part below-ġst part- Patch antenna design with CST microwave (calculation of dimensions)ģrd part- Inset Fed Patch Antenna Simulation and Result In this part of the tutorial, we will use the dimension calculated in the first part to design the patch antenna in CST microwave studio. This is the second part of the Inset fed Patch antenna design tutorial using CST Microwave Studio. The AM schematic with the battery, input port and the load resistor removed is below. The output AM waveform is as shown below. The resistor R6 is just the arbitrary load resistor. The AM RF signal appears at the junction of C6 and C8. The inductor L2 together with capacitors C6 and C8 forms the tank circuit for the buffer. The RF signal at the collector of Q1 drives the modulator or buffer stage Q2. The resistors R2, R4 and R5 are to bias the transistor Q1 and the inductor L1 together with capacitors C7 and C10 forms the tank of the oscillator. The output at the collector of Q2 is the AM signal(in figure labelled AMsignal). The transistor Q1 is part of oscillator that generates carrier signal while Q2 performs modulation of the input signal shown as sine_signal with the carrier signal from the Q1. In this simple AM circuit shown, there are two transistors Q1 and Q2 (2N3904). The final AM circuit that will be designed is shown below.įig: AM circuit design with Altium Designer In this Altium Designer tutorial an AM circuit schematic will be designed and simulated. To do this open the model editor as shown. Now we have to create the symbol library file for the model library. Save the file in some location in your computer.Ģ. Now copy and paste these text into a notepad and save it with name Q2N3904 (or just 2N3904)and extension. The 2N3904 transistor spice model is shown below.
If the model is not available then another way to create the model is to write the pspice model in a simple text notepad by reading the datasheet of the transistor.Īs an example we will show here how to create a pspice model if the pspice is not available in manufacturer website. The pspice model for components are usually available in the manufacturer website.
The first step is to download pspice model for this transistor. Now we will show how to create a simulation model for transistors like 2N3904 but any component like an IC can be added this way.ġ.