Simple Impedance Matched Planar Microwave Blocking Filter

Thermal blocking filters find wide use in cryogenic applications ranging from quantum computing to ultra-low-noise detectors. They can be used to provide the environmental isolation between cooled devices and the warmer temperature supporting bias and readout circuitry. In particular, they are effective in rejecting thermal radiation, limiting radio frequency interference, and providing a convenient means of heat sinking or realizing a vacuum feedthrough for signal lines.