WaveCon  ProCAP Design Examples (1)

ProCAP Low-Pass Cross Coupled Filter

 

Before selecting the filter design, it is necessary to select the tab labeled Units so that the design uses the desired units for the filter design.  The design starts with selecting the tab labeled ‘Design’ and the selection of LC Filt.  This brings up a menu for selecting the type of filter: Low Pass, Band-Pass, High-Pass or  Band-Stop. In this case the lowpass is selected and a menu appears for input of the design parameters.  Upon selecting the type of design a menu appears for placing the desired design parameters.  Selecting the tab “Create Circuit File” results in the nodal design appearing in the ProCAP window.

 

Initially every component has a question mark which were removed except for the first and last capacitor.  Then a cross coupled capacitor was added from the first to the last node with a value of 2 pF.  Without the capacitor, the solid red line is shown.  With the capacitor, the dotted line is shown.

It may be seen that cross-coupling causes some loss reduction out-of-band.  Usually placing the cross coupled element to an internal node will reduce the increase in the out-of-band loss.  The capacitor labeled C1 was modified to improve return loss.  Cross coupling may be made between any two nodes and may be done for any filter type.

Text Box:

Product List

 

 

 

Text Box: