Frequency-agile packaged GaN-HEMT using MIM thickfilm BST varactors

Nowadays wireless communication systems demand flexibility along with electrical efficiency. In this work the highly efficient GaN-HEMT technology is combined with electrically tunable Barium-Strontium-Titanate MIM varactors in parallel-plate configuration, resulting in a frequency-agile transistor module. An efficiency improvement of 19% within a tuning voltage range of 400 V was measured. Maximum CW rating is 44.4 dBm output power at 71.8% drain efficiency. Thermal cycling and modulated-signal measurements verified highly stable and linear operation.