The book focuses on intelligence built into noise instruments and microwave design software. It has a total of 22 chapters and an appendix. This book is intended both for engineers working in practice and students at the technical college level. It not only covers the fundamentals of electronic noise and the properties of semiconductor components but also detailed questions of measurement technology in the low-frequency, RF, and microwave ranges. The book shows what is hidden behind the intelligence built into noise instruments and microwave design software. This book presents many noise issues, starting from simple basics, and each step is presented logically in mathematical derivations. The authors always try to maintain clarity and reference to practice and avoid unnecessary abstract presentations.