Microwave Impedance-Plotting Device

The plotting device described here serves as a computer for the angular position of load points in the Smith Chart for microwaves. By means of a simple mechanical arrangement the computation from measured standing-wave patterns is considerably expedited. The accuracy does not fall off as the distance from generator to probe increases, and in many such cases may considerably exceed that attainable with a slide rule. The gadget should prove useful where reflection measurements at variable frequency are repeatedly required as, for instance, in Q-circle and other resonance measurements.