A Method for Preventing Electrical Short in Impedance Tuners / 14/159,537

Tuesday, January 14, 2014

A method for calibrating and operating electro-mechanical programmable slide screw impedance (load pull) tuners allows avoiding operating in areas where excessive voltage and electric field between the probes and the center conductor is generated. Electrical short through Corona discharge happens both, when the gap between the probe and the center conductor is too small and when the prevailing voltage is too high. The gap must be small if the tuner has to generate a high VSWR in which case the probe position and electric field must be calculated before actually positioning it. The proposed probe positioning technique takes into consideration both limitations, a minimum probe-center conductor gap and the dependence of the standing wave ratio from the actual probe-center conductor gap and electric field. Appropriate calibration and pattern generation solutions are disclosed.