基于Hammer-Head型滤波器结构, 以及三维电磁软件所构建的肖特基二极管三维模型及电气模型, 分别设计了250 GHz悬置微带线和普通微带线的二次谐波混频器。通过仿真设计与实物测试, 对比分析两种结构混频器特性。测试结果表明, 悬置微带线混频器在射频输入230~270 GHz范围内时, 单边带变频损耗为8.6~12.7 dB, 而普通微带线混频器在射频输入220~260 GHz范围内时, 单边带变频损耗为8.4~11.4 dB。通过结果对比可见, 悬置微带线混频器带宽较大, 而普通微带线混频器的变频损耗更为平滑。此外, 考虑微组装工艺中的不良因素, 对仿真模型进行部分修正, 计算结果与测试结果拟合较好。

In order to compare and analyze the characteristics of two kinds of structure mixer through simulation design and measurement, the 250 GHz sub-harmonic mixers of suspended microstrip-line and conventional microstrip-line were designed respectively based on the Hammer-Head filter structure, combined with three-dimensional Schottky diode model and three-dimensional electromagnetic model. The results show that in the radio frequency(RF) range of 230-270 GHz, the conversion loss of single sideband converter was 8.6-12.7 dB for suspended microstrip-line mixer, while that was 8.4-11.4 dB for ordinary microstrip-line mixer with RF range of 220-260 GHz. Contrast results showed that the bandwidth of the suspended microstrip-line mixer was larger than that of the conventional microstrip-line mixer, but its flatness was worse. Finally, considering some undesirable factors introduced in the micro assembly processes, the simulation was calculated and compared with the measuring data, it was found that the results matched well.