MINIATURE LOW-TEMPERATURE HIGH-FREQUENCY FILTERS FOR SINGLE ELECTRONICS

Single-electron devices are now very promising for high-accuracy and high-sensitivity electrical measurements, based on the quantification of the macroscopic charge in metallic nanostructures. The ultimate performance of these devices can only be attained by a careful filtering of the measurement circuit at very low temperature (20 mK). A new kind of wide-band high-frequency filter integrated on a copper block has been designed and studied. This original substrate provides a massive and well-thermalized electric ground plane in the vicinity of the filter. Attenuation measurements show that one has to carefully design the filter box in order to avoid the transmission of electromagnetic modes through the filter box. An improved filter showed -95 dB attenuation at 20 GHz, without any increase of the transmission at high frequency. © 1995 American Institute of Physics.