Arbitrary wideband open-loop active load-pull measurement using Unequally Spaced Multi-Tone stimulus

This paper presents an implementation of active load-pull measurements. This set-up uses the innovative Unequally Spaced Multi-Tone (USMT) wideband test signal in order to assess the in-band linearity degradation of non-linear microwave power devices. The proposed test bench is suitable for both on-wafer and connectorized devices characterization.A proof of concept of the arbitrary wide open-loop active load-pull measurement using 8-tones USMT has been detailed, using 90 MHz bandwidth with a VSWR of 10:1 on an in-house power amplifier. Load tuning is achieved by reinjecting both the carrier tones and third order intermodulation tones at the output of the amplifier.