High-power microwave GaN/AlGaN HEMTs and MMICs on SiC and silicon substrates for modern radio communication

In this paper the recent use AlGaN/GaN high electron mobility transistors (HEMTs) and integrated circuits on both semi-insulating silicon carbide(SiC) and silicon substrates for radio communication in the microwave and mm-wave frequency range is described. AlGaN/GaN monolithically microwave integrated circuits (MMICs) are extremely useful for point-to-point (P2P)-links in the backbones of the 4th and upcoming 5th generation of mobile communication networks as power amplifiers, as they provide a great amount of linear power. At the same time GaN-based power conversion electronics has driven the advancement of the growth of AlGaN/GaN heterostructures on conductive silicon (111) substrates. This again has indirectly led to advancements in the growth capabilities of AlGaN/GaN heterostructures on highly-resistive (HR) silicon substrates. The paper gives examples of transistors and microstrip transmission-line-based MMICs realized in a direct comparison of GaN on s.i. SiC and GaN on HR-silicon. Constraints and performances for highly-efficient MMICs are discussed up tomm-wave frequencies beyond 100 GHz.