Magnetic-free broadband circulator structure based on three switched reflection type delay lines with a total electrical length of 180-degree at the switching frequency is investigated. The nonreciprocal transmission property is modeled and simulated, the impedance mismatching property and reconfigurable direction are studied. A prototype magnetic-free circulator circuit is designed and fabricated using coaxial cables and switches driving by switching frequency of 7.94 MHz with tolerance of ±10%. The nonreciprocal scatter parameters are measured in 300kHz ∼ 100 MHz. It shows that the circulator direction can be reconfigured by changing the switching frequency, and the maximum operating bandwidth equals 1.5f s which is limited by clock feedthrough and spectrum aliasing.

中文翻译：

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基于三切换反射延迟线的无磁宽带环行器分析与建模

研究了基于三个开关反射型延迟线的无磁宽带环行器结构，在开关频率下总电长度为180度。对非互易传输特性进行建模和仿真，研究了阻抗失配特性和可重构方向。原型无磁环行器电路设计和制造使用同轴电缆和开关驱动，开关频率为 7.94 MHz，容差为 ±10%。非互易散射参数在 300kHz ∼ 100 MHz 下测量。结果表明，通过改变开关频率可以重新配置环行器方向，最大工作带宽等于1.5fs，受时钟馈通和频谱混叠的限制。