W波段TWT用硼掺杂金刚石衰减器的热稳定性能研究

The performance and thermal stability of boron-doped diamond attenuator for W-band Traveling Wave Tube

摘要:

针对大功率折叠波导行波管(TWT)对高导热衰减材料的迫切需求，开展了硼掺杂金刚石膜制备和介电性能研究，在此基础上研制出硼掺杂金刚石衰减器并探究衰减器性能的热稳定性。研究结果表明，硼掺杂浓度为1.81×10¹⁹ cm^-3的金刚石膜，在W波段介电常数和损耗角正切平均值分别为7.18和0.30；随着环境温度从室温升高至90 ℃，在85~110 GHz范围内，硼掺杂金刚石衰减器的|S₁₁|由19.67 dB提高至20.94 dB，|S₂₁|由44.03 dB提高至45.63 dB，呈现出较高的热稳定性。

Abstract:

With the fast development of folded waveguide Traveling Wave Tube(TWT), there is an urgent need for attenuation materials with high thermal conductivity and good mechanical properties. In this study, boron-doped diamond film is prepared and the dielectric property of the film is analyzed. Meanwhile, the boron-doped diamond attenuator is fabricated and the thermal stability of the attenuator is investigated. The results show that the dielectric constant and dielectric loss tangent are 7.18 and 0.30 in W-band for the diamond film with boron concentration of 1.81×10¹⁹ cm^-3. Moreover, the return loss and insertion loss of boron-doped diamond attenuator are 19.67 dB and 44.03 dB, respectively. With the temperature increased from room temperature to 90 ℃, the return loss and insertion loss of attenuator are increased to 20.94 dB and 45.63 dB, which demonstrates high thermal stability of the boron-doped diamond attenuator.