Bridged GIC Ladder Filters

Bridged GIC Ladder filters may be used to synthesize delay equalized Chebyshev I filters without the need for all pass stages or coupled inductors.  More information may be found under "Delay Equalizers" -> "Off Axis Real and Quadruplet Zeros" section of the Help, or the short Help video, "Bridged Element Delay Equalization".  

Bridged GIC Ladder filters consist of cascaded shunt GIC stages with a series of one or more bridge resistors connecting the GIC stages on opposite sides of the filter, and are used to formulate off axis zeros, as shown below in Figure 1.

Figure 1.  Bridged GIC Ladder Topology Example

 

Important: To create band pass GIC Ladder filters, band pass, Chebyshev Type I MUST be selected.

Bridged tubular filters may be created from Chebyshev I filters with stop band zeros and off axis real and quadruplet zeros.. The passive circuit schematics will have a check box in the tool bar for "Tubular". Check this box, and a bridged tubular resonator band pass filter will be displayed if the filter design requirements meet all of the all the bridged tubular design criteria If the selected pass band is too wide or other criteria is not met, you will receive an error message informing you that you need to reduce the width of the pass band or instructed to meet other criteria.

Required Criteria:

In addition to requiring Chebyshev I or Elliptic selection, bridged tubular resonator filters must also meet the following:

  1. Band width less than center frequency. To obtain accurate results, the band width should generally be much less than the center frequency.