3D Integrated 300°C Tunable RF Oscillator exploiting AlGaN/GaN HEMT for High Temperature Applications

This work presents the design, implementation, and characterization of a high-temperature tunable RF oscillator utilising a developed 3D integration technology. The circuit is based on an in-house fabricated AlGaN/GaN high electron mobility transistor (HEMT) on sapphire that is vertically integrated on a custom monolithic microwave integrated circuit (MMIC) on quartz, where the lumped passives components are fabricated. The feasibility of the proposed oscillator and technology is proven up to 300°C with frequencies ranging 1000–1040 MHz for different bias voltages. To the best knowledge of the authors, this is the first 3D integrated RF frequency oscillator circuit characterized at 300 °C.