S-parameters are calculated for a bandpass filter in microstrip.
The bandpass filter consists of 8 partially overlapping coupled line filter segments that form 7 resonators each producing one pole. Specifying appropriate values for the block's properties leads to the filter characteristic of the system.
The coupled line sections are built with microstrip coupled lines 4port blocks and microstrip irregular coupled lines blocks. The open ends are terminated with microstrip open end blocks with zero length. Microstrip asymetric step blocks with zero lengths are used to connect sections with different line widths. Since the filter geometry is symmetric the right half is built from the left half by clone blocks. This has two advantages:
Less blocks have to be calculated.
The geometric symmetry of the filter is enforced.
All blocks use the enhanced 2D EM based model for
increased analysis accuracy. Since the bandpass filter uses a lot of blocks
with zero physical dimensions the layout view (available from View
Layout) is better suited to
obtain an impression of the filter geometry than the schematic view.