next up previous
Next: B. Quantum Mechanical Considerations Up: . Previous: 8. Conclusions and Outlook

A. The Active Load-Pull Measurement System

In order to evaluate and match the optimum load of multi-finger high-power transistors the following active load-pull system was established and used to match transistors of $ {\it W}_{\mathrm{g}}$= 480 $ \mu $m and beyond in the Ka-frequency band (26.5 GHz-40 GHz).

Figure A.1: Active load-pull system for 26.5-40 GHz.

\includegraphics[width=14 cm]{D:/Userquay/Promotion/HtmlDiss/fig-50.eps}

The system follows a description given in [298]. A Traveling Wave Tube (TWT) Amplifier is used with a minimum output power of 40 dBm and minimum gain of 50 dB. Devices with an output power up to $ {\it P}_{\mathrm{sat}}$= 352 mW have been be characterized in the Ka-band.