Improvement in Gain Stability of the Superheterodyne Mixer Through the Application of Negative Feedback

The superheterodyne mixer may be stabilized by the employment of the difference-frequency voltage as negative feedback. This results in increased gain stability and, for the case of the mixer couple, in increased gain-bandwidth product. Two mixer circuits using feedback are described. Generalized design curves are shown and a design procedure is outlined. A description of the experimental mixers and a discussion of the experimental results conclude the paper.