We present a novel broadband continuously tunable microwave photonic delay line consisting of a modulator, a four-stage microring resonator delay line, a tunable optical bandpass filter, and a photodetector. Unlike the traditional microring delay lines working at the on-resonant wavelength, the microring resonators in our chip work at the anti-resonant wavelengths, leading to a large delay bandwidth and a small delay ripple. The experimental results show that relative group delay can be continuously tuned from 0 to 160 ps for microwave frequencies in the range of 0 to 16 GHz. The delay ripple is less than 6.2 ps. These results represent an important step towards the realization of integrated continuously tunable delay lines demanded in broadband microwave phased array antennas.

中文翻译：

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基于级联硅微环的宽带连续可调微波光子延迟线

我们提出了一种新颖的宽带连续可调微波光子延迟线，该延迟线由调制器，四级微环谐振器延迟线，可调光带通滤波器和光电检测器组成。与传统的微环延迟线工作于谐振波长不同，我们芯片中的微环谐振器以反谐振波长工作，从而导致较大的延迟带宽和较小的延迟纹波。实验结果表明，对于0至16 GHz范围内的微波频率，相对群时延可以从0至160 ps连续调谐。延迟纹波小于6.2 ps。这些结果代表了实现宽带微波相控阵天线所需的集成连续可调延迟线的重要一步。