为了提高太赫兹行波管的输出功率, 提出了多个传输信号进行功率合成的方法。首先, 对D波段多注慢波结构进行设计及功分器的优化;然后, 通过微铣削工艺完成了两注THz折叠波导结构的加工, 加工精度满足实际设计要求;最后, 利用CST软件对该结构的冷测与互作用特性进行了分析。仿真结果表明: 该结构的S11值小于-20 dB, 实际测试值在-20 dB左右, 两者较吻合。冷测分析表明该结构具有22 GHz(16%)的冷带宽, 3 dB增益带宽为12.5 GHz。在各电子注的电压、电流、峰值输入功率大小分别为15.79 kV, 12 mA, 10 mW时, 单注结构获得了1.58 W的输出功率及22 dB的增益;而两路信号在互作用完成后, 获得了2.91 W的合成功率输出, 合成效率不低于90%。通过合成的方法可以有效提高THz行波管的输出功率。

To enhance the output power of Terahertz (THz) Traveling-Wave Tubes (TWT), a new proposal about power combining of multiple signal is presented in the paper. Firstly, the design of D band Two-Beam Folded Waveguide Structure (TBFWS) was completed and the power divider was optimized. Then, a TBFWS was fabricated by micro milling, and its dimensions errors are below the designed values. Lastly, the cold-test and interaction characteristics of TBFWS were analyzed by CST code. The simulation results show the S11 of TBFWS is below -20 dB, and the experiment results demonstrate the S11 of TBFWS is about -15 dB. The dispersion characteristics of the TBFWS show the circuit has a broad cold bandwidth of 22 GHz (16%) and 3 dB bandwidth of 12.5 GHz. With the 10 mW input peak power, 10 mA beam current and 15.79 kV beam voltage of each FW circuit, the gain and output power of single beam FW-TWT are 22 dB and 1.58 W at 0.14 THz, respectively, whereas, the TBFWS circuit can produce the combining output power of 2.91 W at 0.14 THz. Power combining efficiency of the circuits is more than 90%. The power combining method can efficiently enhance the output power of THz TWT.