Various critical analog, mixed-signal, RF and digital circuits are used in all space-based platforms, including DoD space systems (communication, surveillance, ballistic missiles, missile defense), and commercial satellites. Since modern electronics technologies and components are becoming increasingly sensitive to extreme environments, the mission lifetime and reliability are becoming increasingly critical, and the capability to predict their behavior dramatically increases confidence and reduces risk. The new RHBD designs and circuit/cell libraries, as well as the physics-based computer aided design (CAD) tools, can also be applied to cryogenic electronics for high-sensitivity, low-noise analog and mixed-signal applications, such as metrology, infrared (IR) imagers, sensors (radiation, optical, X-ray), radiometrology, precision instruments, radio and optical astronomy, infrared and photon detectors, and other high-end equipment. For all such devices and systems, predictive and accurate modeling and design tools reduce the amount of required radiation/temperature testing, thus decreasing their cost, and time to market or field application. Prediction of electrical performance and radiation tolerance of electronic components in extreme environments (wide temperature range, radiation) are crucial for designing reliable electronics for all NASA robotic exploration missions, such as planned Europa Jupiter System Mission, Titan Saturn System Mission, Venus In-Situ Explorer, sample return from Comet, Asteroids, and continued lunar and Mars exploration missions. Since electronic parts are getting smaller with technology evolution, the radiation/temperature effects are becoming more severe ¬ñ the lifetime and reliability are quickly becoming critical issues ¬ñ the physics-based capability to predict the behavior of electronic circuits increases confidence and reduces mission risk. Radiation-hardened and wide-temperature analog, mixed-signal, RF and digital circuits are essential for all the avionic systems used in the NASA exploration projects. The optimized, wide-temperature RHBD designs from this SBIR will add to the pre-existing NASA "component library". The wide-temperature, physics-based mixed-mode tools will help NASA to design rad-hard low-temperature electronics with better understanding and control of design margins, and will enable designers to better evaluate the wide-temperature performance and radiation response at an early design stage and set requirements for hardening and testing, thereby reducing the amount of testing time and cost.