Experiments on X-Band Automatic Impedance Measuring Scheme Using Three Fixed Probes

Resulting from a two-month visiting research a t National Bureau of Standards, Boulder, Colorado, this Summer, the author was able t o virify w i t h real-time oscilloscope display, the theory he published two years ago conceming automatic impedance measuring schemes us ing multiple probes, (IEEE Trans. MTT, Dec. 1980). The system consists of three, non-resonating probes mounted on an X-band waveguide. The diode detected o u t p u t s from these probes are fed into a d.c. s i g n a l processor designed according to the theory described i n the quoted paper. The two outputs of the s i g n a l processor are then connected t o the x,y i n p u t s of a storage oscillo41