First demonstration of heterogeneous integrated limiter chip with breakdown-enhanced GaN SBDs

In this paper, we demonstrated a high power heterogeneous integrated limiter chip with a breakdown-enhanced GaN SBD for the first time. By replacing the conventional thick GaN buffer with a thin AlN buffer layer, the breakdown voltage of the GaN Schottky barrier diode (SBD) was enhanced by a factor of 2.4 without significant degradation of other electrical characteristics. The device achieved a breakdown field strength of 1.2 MV/cm and a Johnson's figure of merit (J-FOM) of 47.2 THz$\cdot$V. Capitalizing on the superior breakdown performance of this GaN diode, a novel hybrid cascaded self-sensing limiting architecture was proposed, and a heterogeneous integration process was developed to co-fabricate GaN SBDs, Si PIN diodes, on-chip capacitors, and microstrip lines on a GaN-on-SiC substrate. A limiter chip operating from 0.5 to 4.8 GHz is designed and implemented, exhibiting continuous-wave power handling capabilities of 200 W at 2 GHz and 100 W at 4 GHz. These results validate the effectiveness and advancement of the proposed device design, circuit topology, and integration technology, highlighting their strong potential for next-generation electromagnetic protection applications.