Broadband Driver Amplifier with Voltage Offset for GaN-based Switching PAs

The paper presents a GaN-based driver amplifier (PSA) module with potential shifting included, suitable for proper driving GaN-HEMTs with digital bit sequences in the microwave range. The PSA is capable of driving a GaN-HEMT with 5 Vpp input swing from a standard 1 Vpp signal. Additionally, it provides a controllable potential shift (DC-offset) between -1.9 V to -10.9 V when referenced to GND. A voltage gain of 10.7 and 4.9 with a load of 1 kΩ || 0.25 pF and 50 Ω is achieved, respectively. Input of the PSA is referred to GND with 50 Ω input impedance. The bandwidth is DC - 3.2 GHz for a 3 dB voltage gain drop for both loads applied. The proposed PSA is an important part to complete digital signal chains and can be also used as analog amplifier.