A novel millimeter-wave ballasted stacked-transistor configuration implemented on a 0.7 μm InP double heterojunction bipolar transistor (DHBT) process is proposed in this paper. A ballasting resistive network connected to the emitter leads of the common-base stage proves to be very effective in extending the safe operating area (SOA) of a unit power cell. Electromagnetic-circuit co-simulations based on a DHBT large-signal model including thermal effects show a significant increase of the attainable voltage swing under RF operation. Experimental results at E-band obtained from a two-stage monolithic microwave integrated circuit (MMIC) power amplifier validate the analysis and design. A small-signal gain of 13.9 dB at 71 GHz and an output power higher than 17.3dBm at 75 GHz have been observed experimentally on the fabricated MMIC.
- Power amplifier
- Indium phosphide
- Double heterojunction bipolar transistor (DHBT)