JOSEPHSON FREQUENCY MIXING BETWEEN TWO K_a BAND SIGNALS IN CERAMIC BRIDGE AT LIQUID NITROGEN TEMPERATURES

【摘要】 <正> Ⅰ. INTRODUCTION Josephson mixers at liquid helium temperatures have attracted the attention of many authors because of their low noise, high conversion efficiency and broad bandwidth which are essential for application at millimetre and submillimetre wavelengths. However, the requirement of extremely low temperatures for their proper operation has limited the applications to very specific purposes. The newly discovered high T。superconducting materials at liquid nitrogen temperatures have made pos-更多还原