Parametric upconvertors as receiver first mixers at high frequencies

The system requirements of h.f.receivers make unusual demands on any parametric upconvertor designed to form the first mixer stage. These requirements are considered in detail and design equations formulated for two upconvertors, both of the four-frequency type with wanted sideband power extracted at upper- or lowersideband frequencies, respectively. It is demonstrated that values of gain, noise figure and port impedances may be obtained that are compatible with system requirements. The design of an experimental upconvertor is described, and the observed performance is shown to agree with the theoretical predictions