Fabrication of Three-Pole HgBa2CaCu2O6+δ Hairpin Filter and Characterization of Its Third Order Intermodulation

The increased research interest in the microwave applications of high temperature superconductors (HTS) was brought about by the perceived potential on the marketability of superconducting electronics, especially in the wireless communications industry. Excellent surface morphology and high reproducibility of the HgBa₂CaCu₂O_6+delta (Hg-1212) thin films made from cation exchange process has motivated us to develop microwave bandpass filters, which can be operated at above 77 K and therefore are much more cost effective. An Hg-1212 three-pole hairpin filter of 5% 3-dB bandwidth has been fabricated and characterized. The transmission properties and third-order inter modulation (IM3) measurements on the filter have demonstrated Hg-1212 as a promising alternative material for passive microwave devices at above 77 K operating temperature.