Estimation of Load-Pull Reflection Coefficients for Modulated Signals

A method to estimate reflection coefficients in a loadpull environment with modulated signals is proposed, which can be applied during the design stage and characterization of devices and components for next generation systems. The technique is based on least-square estimation of the impulse response of a finite impulse response filter. The proposed technique along with the conventional method are described and analyzed theoretically. The two approaches are experimentally demonstrated, verified, and compared using a load pull measurement setup with 6W GaN power amplifier as the device under test. The proposed technique shows better performance for both in-band and out-of-band estimation of reflection coefficients.