Wafer-Type Millimeter Wave Rectifiers

Point-contact rectifiers for millimeter waves have been in experimental use for several years. These units, for the most part, have been coaxial cartridges which were inserted in a fixed position, usually centered, in the waveguide. Impedance matching was accomplished by means of a series of matching screws preceding the rectifier and an adjustable waveguide piston following the rectifier. Tuning screws are generally undesirable because of the possibility of losses, narrow bandwidths and instability. It is the purpose of this paper to describe a new type millimeter-wave rectifier and holder which were designed to eliminate the need for tuning screws and to provide a readily interchangeable rectifier of the flat wafer type. This wafer contains a short section of waveguide across which the point contact rectifier is mounted. The necessary low frequency output terminal (and the rectified current connection) together with the highfrequency bypass capacitor, are also contained within each wafer. The basic idea of the wafer-type rectifier is that the unit can be inserted in its holder and moved transversely to the waveguide to obtain a resistive match to the guide; the reactive component of the rectifier impedance is then tuned out by an adjustable waveguide plunger behind the rectifier. * This work was supported in part by Contract Nonr-687(00) with the Office of Naval Research, Department of the Navy.