In high-reliability applications such as aerospace, satellite communication, and nuclear control systems, multiple node upsets (MNUs) induced by radiation have become a major threat to the stability of static random access memory (SRAM). In recent years, to address the double node upset (DNU) issue, various radiation-hardened-by-design (RHBD) structures have been proposed and extensively studied, including S8P8N, QUCCE12T, SARP12T, HRLP16T, RH20T, S6P8N, and RH14T.