Properties of Welded Contact Germanium Rectifiers

In the contact rectifier described, the cat whisker has been solidly welded to a germanium surface. The welding process has brought about several extraordinary properties not found in the usual point rectifier: (1) Mechanical stability is achieved without the use of a compound to fill the cartridge. Protection against moisture is gained through the use of a glass‐metal seal. (2) The forward dynamic resistance of the microwave unit at 0.5 volt is exceptionally low (2 to 4 ohms), and the back resistance at 0.5 volt is high (0.01 to 1.0 megohm). These values of resistance are accompanied by a low contact capacity at zero bias (below 0.2 μμf). (3) The forward d.c. characteristic follows the law, IF=I0 exp (αVF) over more than three decades of current. (4) The low forward resistance is responsible in part for conversion gain when the crystals are mismatched to microwave radiation at the r‐f terminals. (5) Specially welded crystals used as microwave harmonic generators have yielded more than twenty times the ha...