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现代机载导弹系统中炮瞄雷达的能力,主要取决于雷达发射机末级的行波放大器。在这类系统中工作的器件,在X波段应能提供高的平均功率,大于50分贝的射频增益以及具有栅极调制。在一个轻重量的管子里获得高平均功率所广泛采取的办法,是把磁箔精确地绕在管子的高频回路上,这是一种先进的线包聚焦方法。用于机载雷达的其它一些行波管,采用周期永磁聚焦以获得较小的尺寸、较轻的重量和较简单的设计。这些限于较低的平均射频功率,但能在X和Ku波段给出100千瓦以上的峰值射频功率。在不调谐的情况下,这类系统能在1000兆赫带宽内提供相当大的防护电子对抗和相互干扰的能力。近五年来,这些放大器的转换效率通过使用渐变回路,多级降压收集极和电压跳变回路等技术,已经稳固地获得提高。当今,设计一个用于机载环境下效率超过50%的实际器件,已是很普遍的事情了。
The capability of gun sight radar in modern airborne missile system mainly depends on the traveling wave amplifier of the last stage of the radar transmitter. Devices operating in such systems should provide high average power, RF gain greater than 50 dB, and gate modulation in the X-band. A widely adopted approach to achieve high average power in a lightweight tube is to accurately wrap the foil around the tube’s high-frequency loop, an advanced method of line-focusing. Other traveling wave tubes used for airborne radar use periodic PM focusing to achieve smaller size, lighter weight and simpler design. These are limited to lower average RF power, but give peak RF power of over 100 kilowatts in the X and Ku bands. Without tuning, such systems provide considerable protection against electronic countermeasures and mutual interference within a bandwidth of 1000 MHz. In the past five years, the conversion efficiencies of these amplifiers have steadily improved through the use of techniques such as gradient loops, multi-stage buck collectors, and voltage trip circuits. It is already a common practice today to design a real-world device that is more than 50% efficient in airborne environments.