Prospects of using the Schottky-Barrier Composite Two-Tier FETs in a HIC of the Microwave Power Amplifiers

The paper demonstrates relevance and prospects of using the Schottky-barrier composite two-tier FETs based on the GaN crystals in the previously developed hybrid integrated circuit design, as well as the possibility to increase power dissipation up to 200 W with using one pair of crystals and to 250 W with using the two pairs. Thermal calculation results are presented proving the prospects of using the proposed hybrid integrated circuit design. Crystals of the two types GaAs and GaN are compared. Efficiency and prospects for using GaN crystals and Schottky barrier composite two-tier field-effect transistors in a hybrid integrated circuit of the microwave power amplifier could significantly improve its weight and size characteristics. Advent and use of the Schottky-barrier field-effect transistors based on the GaN crystals with the power of up to 100 W and more was temporarily solving the problem of increasing the power and improving the weight and size characteristics of the microwave amplifiers. When comparing maximum temperatures on the transistor crystal at the released power of 1 W, it was found that an increase in the thermal conductivity of the additional heat sink contributed to maximum temperature displacement from the upper crystals to the lowers and changed the heat flow direction. GaN crystals use increased the power level over the entire range of thermal conductivity of the additional heat sink materials 500--2000 W/(m · K), and the power ratio with an increase in the thermal conductivity of the additional heat sink was approximately equal to two. Prospects of using the proposed design of a hybrid integrated circuit of power amplifiers was justified