The Design of Miniaturized Superconducting Filters With the Reflected Group Delay Method

The reflected group delay method can be used to design higher-order superconducting filters. A correction factor is introduced to ensure that the reflected group delay response is symmetric about the center frequency. The method is demonstrated through the design of an eight-pole lumped-element filter using a circuit simulator. A miniaturized high-temperature superconducting eight-pole filter and a highly miniaturized lumped-element low-temperature superconducting eight-pole filter are designed using this method, and their measured results are reported.