An Algorithm for Using a Slide-Screw Tuner as a Computer-Controlled Impedance

In the testing of active microwave components, a common test procedure is to evaluate a device´s performance when subjected to an all-phase, constant-standing-wave-ratio (APCS) load pull. Such a test specification is useful in verifying a device´s stability and mismatch performance. Typically, APCS pulls are tediously performed by hand, with manually operated tuners. However, with the advent of mechanical, computer-controlled tuners, it is now possible to automate this procedure.