非均匀磁场下14叶片5.8GHz磁控管的三维数值模拟

3-D simulation of 14 vanes 5.8GHz magnetrons in non-uniform magnetic field

频谱噪声的抑制问题一直是磁控管的研究重点。对14叶片5.8GHz磁控管进行了三维建模,包括阴极、叶片、隔膜带、极靴和输出天线等。使用冷腔模拟得到了π模腔体频率5.86GHz。热腔模拟计算得到7个电子轮辐,说明管子在π模正常工作。在某种极靴结构下,计算得到腔体中存在一个近似二次曲线的非均匀磁场分布。在阳极电压4.5kV、非均匀磁场中心值0.289T时,模拟得到输出频率5.891GHz,阳极电流1.55A,输出功率4.9kW,电子效率70.3%的结果。输出频谱比较干净,抑制了非π模式的工作,提高了工作效率。

The suppression of the frequency spectrum noise is the key in the magnetron research. The performance of 14- vanes 5.8 GHz strapped magnetron is modeled, including cathode, vane, straps, pole pieces and output antenna. The cavity fre quency is 5.86 GHz in the cold cavity simulation. Seven electron spokes confirm the rr mode works in the oscillation cavity region by the hot simulation. A non-uniform magnetic field distribution is calculated as a conic section curve by the pole structure in the model. When beam voltage is 4.5 kV, the anode current is 1.55 A and the axial value of the non-uniform magnetic field is 0. 289 T, the output frequency 5. 891 GHz and output power 4.9 kW in the hot test simulation are obtained. The efficiency of the elec tron interaction is 70. 3%. The remarkable improvement in the frequency spectrum and the electron efficiency are achieved by suppressing the RF harmonic content.