6.4 Large-Signal Measurements

To evaluate the high-power performance of transistors with a gate width of ${\it W}_{\mathrm{g}}$$\geq$ 500 $\mu$m a load-pull measurement system was set up for the Ka-band frequency band (26.5-40 GHz) [298]. The description of the load-pull system can be found in Appendix A. Using this system a systematic study is performed to evaluate and compare different HEMT designs with respect to high power performance between 30 GHz and 40 GHz.