What is microwave, how was it discovered, how do people use electromagnetic waves, and how to design microwave circuits and antennas? This course will answer the above questions from five parts: waves, space waves, guided waves, antennas and radio waves, and wave networks. . This course uses unified viewpoints, unified thoughts and unified methods to systematically discuss microwave concepts, theories and applications from a new perspective and answer the above questions. The course is aimed at undergraduates and graduate students majoring in electronic information engineering, communication engineering, electronic science and technology, etc. in colleges and universities, and can also be used by relevant engineering and technical personnel.