Design and development of high linearity millimeter wave traveling-wave tube for satellite communications

• 作者: 何俊 李海强 李现霞 李跃 赵建东 赵石雷 赵磊 黄明光
• 来源期刊: 中国物理B（英文版）
• 关键词: helix traveling-wave tube digital modulation nonlinear distortion pitch profile optimization
• 年，卷（期）: 2015,（10）
• 页码范围: 104102-1-104102-5
• 页数: 1页
• 语种: 英文
• DOI: 10.1088/1674-1056/24/10/104102

摘要

The linearity of the traveling-wave tube is a very important characteristic for a modern communication system. To improve the linearity of the traveling-wave tube at no expense of the saturated output power and overall efficiency, a modified pitch profile combined with a small adjustment of operating parameters is proposed. The optimal design of the helix circuit is evaluated theoretically by a large signal analysis, and the experimental test is also carried out to make a comparison of performance between the novel and original designed traveling-wave tubes. The experiments show that the saturated output powers and efficiencies of these two tubes are close to each other, while the linearity of the traveling-wave tube is obviously improved. The total phase shift and AM/PM conversion at saturation of the novel tube, averaged over the operating band, are only 30.6?/dB and 2.5?/dB, respectively, which are 20.1?/dB and 1.6?/dB lower than those of the original tube, respectively. Moreover, the third-order intermodulation of the novel tube is up to 2.2 dBc lower than that of the original tube.