A Fast Two-Tone Active Load-Pull Algorithm for Assessing the Non-linearity of RF Devices

Radio frequency (RF) devices used in modern wireless systems must meet increasingly complicated spectral constraints while still operating with high power efficiency. A fast real-time two-tone active load-pull algorithm is proposed to assess the relationship between nonlinear performance with associated device load impedance variations. This algorithm employs real time measurement data to extract two-tone local nonlinear behaviour model, which is further used for the prediction of injected signal value in the active real-time load-pull system, therefore minimizing the number of iterations required for load emulation. The proposed method was validated on a real two-tone load-pull measurement bench using off-the-shelf instruments. The result shows that the measurement speed has been greatly increased without sacrifice of the impedance emulation accuracy. This intelligent two-tone load-pull algorithm is expected to be applied in the designing of modern communication system and radar transmitters, as well as the validation of the models of radio frequency transistors.

Automated summary

This article introduces a fast real-time two-tone active load-pull algorithm to evaluate the nonlinear performance of RF devices in wireless systems. The algorithm extracts a nonlinear behavior model using real-time measurement data, and predicts the injected signal value in the active load-pull system, improving the measurement speed.