All of the measured results include the fixture with SMA connectors and line losses leading to and from the filter.  Consequently, the return loses are degraded with increasing frequency. None of the filters were tuned to optimize performance.

LOW PASS FILTER ON ROGERS 6002, .01 INCHES THICK

15.15 GHz PARALLEL COUPLED LINES BANDPASS FILTER ON ROGERS 6002, .01 INCHES THICK

4.075 GHz INTERDIGITAL BANDPASS FILTER ON ROGERS 6002, .01 INCHED THICK

6.5 GHz INTERDIGITAL BANDPASS FILTER ON N4380-13 RF MATERIAL, .012 INCHED THICK(FR4 TYPE MATERIAL)

1.050 GHz INTERDIGITAL BANDPASS FILTER ON ROGERS 6002, .01 INCHED THICK