This paper presents an active load-pull test bench in the Ka band using an ABmm network analyzer. The test bench is fully automated and it allows the small signal S-parameter and the input-output power characteristic meausrment of transistors or amplifiers. The load-pull characterization of transistors using a probe station can be carried out with a classical active load-pull technique or with an active loop. An alternative approach for the on-wafer calibration procedure is described. Results on high gain power amplifiers are presented. A load-pull characterization of a transistor is also given and comparisons with simulations validate the measurements.