RF Electronics Chapter 2: Computer Simulation Page 8
2022, C. J. Kikkert, James Cook University, ISBN 978-0-6486803-9-0.
Now place all the other capacitors and inductors in the correct location. When placing the
component, a right mouse click rotates the component. Selecting the port symbol from
the mini toolbar, or selecting Draw Add Port allows the input and output ports to be
added to the circuit. Draw Add Ground allows a ground connection to be added.
Double Left Click on a component or on the property's text in the schematic, allows the
required value for that component to be entered. Repeat this for all the other components
to result in the final circuit as shown in figure 2.3.
Note that normally filters are designed with the smallest number of inductors, so that odd
order filters with the end elements being capacitors are far more common.
Practical Note: The filters are to be used as part of a diplexer, consisting of a high-pass
and a low-pass filter in parallel. The high-pass filter must not short out the low-pass filter
at low frequencies and the low-pass filter must not short out the high-pass filter at high
frequencies, so that an open circuit input impedance is required in the stopband of these
filters. This is achieved with the first (series) element being an inductor for the low-pass
filter, and the first element being a capacitor for the high-pass filter.
Figure 2.3. Low-pass filter circuit.
Figure 2.4. "Add Measurement" window.
RF Electronics: Design and Simulation
8 www.cadence.com/go/awr
