ABSTRACT

Fast tuning and measuring algorithms in open loop active load pull systems have been developed to accommodate high speed production testing of many chips of the same kind on wafer; they are based on re-setting the (pre-calibrated) amplitude and phase of the injected power into the device output port. Because of the dispersion of the chip characteristics this often leads to non-physical load synthesis, i.e. lGammal> 1, which not only is unrealistic test condition, but also risks destroying the device under test, or reflection factors not high enough to reach the optimum Gamma of the DUT. A method is proposed to use a mechanical tuner in order to shift the active tuning inside meaningful areas; the tuner is also used to pre-match the device to the injection amplifier.

Filed: 3 November 2014

Allowed: 2 June 2016

Issued: 2 September 2016