An Improved Active Load-pull Setup for Transistors Large Signal Characterization in the Ka Band

This paper presents an original active load-pull test bench for active device characterization in the Ka band. The setup enables measurement and optimization of load conditions for power operation using a modified active load pull technique with pre-matching. The proposed modified active loop with pre-matching offers a larger load reflection coefficient with higher linearity of the loop amplifier. Furthermore, a switch placed between the pre-matching circuit and the loop provides greater automation of the system: calibration, S-parameter and active load-pull measurements with pre-matching or not, can be carried out without dismantling components of the bench. Experimental characterization at 30 GHz of a GaAs PHEMT power transistor is presented as well as the results of the one-stage amplifier that was designed using the transistor load-pull characterization