Reliability of Operating Electronic equipments on board of artificial satellites, spacecrafts, and military aircraft's in extreme environment require radiation hardening. The effects of radiation, both single event and total ionization dose on the phase frequency detector, voltage controlled oscillator, charge pump and filters for PLL application are studied. The focus is on and CMOS based technologies; however, other high performance technologies will be discussed wherever appropriate. The points of concern are single event effects (SEE) and steady state total ionizing dose (TID) IC response. Specific design architecture and techniques are implemented including radiation effects, radiation hardening technique, PLL building blocks and the overall performance to help mitigate radiation effects that degrade PLL performance. This book aims towards the design and analysis of a radiation hardening of all individual components of Rad-hard PLL starting from process simulation and device simulation to Circuit simulation using 0.5um CMOS library.