This book presents the basics of building various types of amplifiers, the most widely used in the composition of modern specialized radio receivers, as well as the principles of building digital radio receivers. The rapid development of modern telecommunications systems, aviation equipment, and space systems for various functional purposes, as well as new information technologies, is inextricably linked with the theory of building radio receivers. Radio receivers are an integral part of the radio line, which largely determine the quality of its operation, both in normal operating conditions and in a complex interference environment. Since the creation of the first lightning detector in 1895, the technique of radio receiving devices went a long way to the development of modern automated digital systems. 

Sergey Viktorovich Dvornikov is a Doctor of Technical Sciences, Professor, Honored Inventor of the Russian Federation, Professor of the Department Radio Engineering and Optoelectronic Complexes of the St. Petersburg State University of Aerospace Instrumentation. He is the Author of more than 100 patents for inventions of the Russian Federation. Full Member of the International Academy of Authors of Scientific Discoveries and Inventions. His research interests are in the areas of advanced radio communication facilities and complexes.

Alexander Fedotovich Kryachko is Honorary Worker of Higher Professional Education, Professor, Doctor of Technical Sciences, Head of the Department of Radio Engineering and Optoelectronic Complexes at St. Petersburg State University of Aerospace Instrumentation, academician of the International Academy of Communications. . Author of about 140 scientific papers, including 3 monographs, and7 textbooks. His research interests are in the areas of diffraction of electromagnetic waves on complex bodies, the study of the scattering of electromagnetic waves on radar reflectors and aircraft with anti-radar coatings. 

Igor Anatolyevich Velmisov is Professor, Doctor of Technical Sciences, Professor of the Department of Radio Engineering and Optoelectronic Complexes, Institute of Radio Engineering, Electronics and Communications, St. Petersburg State University of Aerospace Instrumentation. Author of 120 scientific papers, including 1 monograph, 11 textbooks, 1 patent. His research interests are in the areas of flight safety issues in air traffic control and radio engineering support for civil aviation aircraft flights.

Dmitry Alexandrovich Zatuchny is Doctor of technical sciences, Associate Professor, and Professor at the Department of Computation Machines, Complexes, Systems and Networks at Moscow State Technical University of Civil Aviation. He is the Author of more than 140 scientific works, including 5 monographs, 6 textbooks, 1 patent on an invention, and 6 state-registered computer programs. He was responsible for a number of research projects on ensuring the functioning of modern navigation systems in civil aviation aircraft and air traffic control.

Introduction.- Chapter 1. Technical characteristics and block diagrams of radio receivers.- Chapter 2. Noise ratios in the receiving devices.- Chapter 3. Circuit fundamentals of input circuits and selective amplifiers.- Chapter 4. Selective amplifiers. Principles of optimization of their parameters.- Chapter 5. Multi-stage single-circuit selective amplifiers.- Chapter 6. Frequency converters.- Chapter 7. Low-noise amplifiers.- Chapter 8. Radio signal detectors.- Chapter 9. Adjustments in radio receivers.- Chapter 10. Digital radio devices.