Microwave Power Engineering 2. [antikvár]

PREFACE This book introduces the new electronics technology of microwave power and its applications. This technology emphasizes microwave (and eventually quantum) electronics for direct power utilization and transmission purposes rather than exclusively for information and communications applications. Because only fixed frequencies are involved in most present applications, phase and delay distortions as well as bandwidth and coherence considerations, associated with information transmission systems, are less important. Essentially, microwave power can be divided into microwave heating, microwave processing, microwave dynamics, and microwave power transmission involving generation and power amplification, direct power utilization, and closed waveguide or radiation beam propagation for remote utilization and rectification. Emphasis is on: (1) the microwave frequency spectrum, in relation to minimum size, specific weight (i.e., power/unit weight), and cost considerations; (2) constant or continuous wave (CW) rather than periodic pulsed power; (3) very high efficiency; (4) reliability; and (5) long life. While the proceedings of the first symposium on this subject have been reviewed in the October, 1964 issue of IEEE Spectrum, a thorough coherent introduction to this subject now seems timely. In particular, this book seeks to present a review of the state-of-the-art accomplishments with respect to components, systems, and applications and their prevailing limitations in the light of modern knowledge of the microwave power technology. Recommendations are included with respect to what can be done to accelerate a balanced growth of the subject and to attract more creative interest and support. The dominant microwave state-of-the-art generators and power amplifiers, with respect to power capabilities and efficiency, include the magnetron, the Amplitron, and the klystron, whereas the magnetron has been found most suited to the widely varying impedances associated with batch processes. The dominant state-of-the-art microwave rectifiers, in this same respect, include the thermionic (ultra-close spaced, vacuum, electrostatic) diode, the point contact and Schottky barrier semiconductor diodes, and the (electrostatically focused) inverse klystron. Other theoretically promising microwave rectifiers include the transverse wave and traveling-wave devices. Microwave heating and other processes of materials, including food, utilize the magnetron predominantly, and also the klystron, in drying and freeze drying, sealing, cooking, reheating, thawing, moisture leveling, etc. Other applications include (1) microwave ionized gases presently on an experimental basis for chemical processing, space (propulsion), and scientific (controlled nuclear fusion) purposes; (2) particle accelerators for scientific, medical, and industrial purposes; (3) military and aerospace for phased array focused microwave energy, experimental vehicle hovering, etc; and (4) dynani-ics, for experimental microwave motors and experimental waveguide vehicle transport, etc. Besides these applications of microwaves and those under .i'm^r /'Vi'h^: : -¦ Mi'-r E.