This paper presents a design of magnetless microstrip line circulator with filtering response and extended isolation bandwidth through integration of mixed static and time-modulated resonators. By effectively coupling static resonators with time-modulated resonators, the proposed circulator can achieve a low forward transmission insertion loss with filtering response along with a wide isolation bandwidth. Wideband isolation can be achieved by creating two isolation nulls within the passband. For proof-of-concept, a microstrip line circulator is designed, simulated, and fabricated at center frequency of 1.75 GHz. The measured results are well agreed with simulations. The measurement results show maximum forward transmission insertion loss of 2.70 dB, in-band 20-dB isolation of 80 MHz, and in-band return losses better than 18 dB.

中文翻译：

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使用混合静态和时间调制谐振器增强隔离带宽的无磁滤波环行器

本文提出了一种无磁微带线环行器的设计，通过集成混合静态和时间调制谐振器，具有滤波响应和扩展的隔离带宽。通过将静态谐振器与时间调制谐振器有效耦合，所提出的环行器可以实现低前向传输插入损耗、滤波响应以及宽隔离带宽。宽带隔离可以通过在通带内创建两个隔离零点来实现。为了进行概念验证，我们以 1.75 GHz 的中心频率设计、仿真和制造了微带线环行器。测量结果与模拟结果非常吻合。测量结果显示，最大前向传输插入损耗为 2.70 dB，带内 20 dB 隔离度为 80 MHz，带内回波损耗优于 18 dB。