Abstract: A frequency converter that includes a first low-pass filter and a band-pass filter with a first end operatively connected to a first end of the first low-pass filter. The frequency converter also includes a second low-pass filter with a first end also operatively connected to the first end of the first low-pass filter. The frequency converter, moreover, includes a first waveguide with a first end operatively connected to a second end of the second low-pass filter, with the first waveguide containing at least one frequency-mixing element, and with the first waveguide continuing for a specific length after the one frequency-mixing element and having a second end that is operatively short circuited. The frequency converter, furthermore, includes a second waveguide operatively connected to the one frequency-mixing element. The frequency converter is arranged such that the specific length of the first waveguide extends past the operative connection between the second waveguide and the one frequency-mixing element.

Abstract: The following description regards a frequency converter (1) for applications on millimetric radio waves. The circuit structure comprises a diplexer filter realized in thin film on an alumina layer connected to a balun set up by a quartz plate on which two mixing diodes in GaAs have been mounted, placed in the center of a rectangular cavity (2) closed on one side by a short circuit plate and on the opposite side communicating with a rectangular waveguide (4) transporting a radio frequency signal (RF). On the upper side of the plate three parallel metallic bands have been put in the sense of the width of the cavity, between the bands the diodes are connected in series. The most external bands are welded to the walls of the cavity (2), the central one on the other hand is connected to the point common to both sections of the diplexing filter by means of a metallic strap in the air welded to a microstrip.