A Printed Circuit Stub Tuner for Microwave Integrated Circuits

A novel microwave tuning eIement capable of continuous adjustment has been realized in the form of a planar printed circuit. As such, it is suitable for incorporation into microwave integrated circuits (MIC's), where it can be used for fine-tuning the impedance match between two parts of a circuit when the two parts are either subject to variations due to manufacturing tolerances or are difficult to model. In either case, the tuner is a compact on-circuit tuning facility which does not have to be removed after use. The tuner has been shown to have unique impedance-transforming properties, being capable of matching any realizable impedance to a 50-Omega load. Its main part consists of a coupled-line section and across the gap in the sectiou at different places along its length are positioned two short-circuit bridge conductors. Movement of these bridges produces the variation in impedance transfomration.