20年来世界各国发射的各类通信卫星,绝大多数均采用行波管。但近几年来,美国已经和将要在某些军用通信卫星和国内通信卫星上采用固态功率放大器(参见本刊第二期《西方各国通信卫星上采用的行波管》一文)。和行波管相比,固态微波器件的低压工作特性,及其长寿命高可靠性等优点,增强了它在卫星上应用的优势。随着效率的提高和功率合成技术的发展,固态微波功率器件将会在某些频段上得到广泛应用。国外有人认为,20千兆赫以下中小功率(10瓦以下)的固态微波器件很有可能逐步代替星上行波管。至于固态微波器件能否代替行波管,目前国外尚有争论。本期选译的一组文章试图从不同侧面反映它们的发展动向。 Over the past 20 years, all kinds of communications satellites launched by various countries in the world have adopted traveling wave tubes. However, in recent years, the United States has and will adopt solid-state power amplifiers on some military communications satellites and domestic communications satellites (see issue 2 of the article “Traveling Wave Tubes Used in Communication Satellites in Various Countries in the West”). Compared with TWTs, the low-voltage operating characteristics of solid-state microwave devices, as well as their long life and high reliability, enhance the advantages of its application on satellites. With the improvement of efficiency and power synthesis technology, solid-state microwave power devices will be widely used in some frequency bands. Some people think that abroad, 20 gigahertz following small and medium-power (10 watts) solid-state microwave devices are likely to gradually replace the star uplink wave tube. As for the solid-state microwave devices can replace the traveling wave tube, currently there is still controversy abroad. A series of articles selected for this issue try to reflect their development trend from different aspects.