Highly Sensitive Coupled Oscillator Based on an Exceptional Point of Degeneracy and Nonlinearity
Highly Sensitive Coupled Oscillator Based on an Exceptional Point of Degeneracy and Nonlinearity
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DOI：
10.1103/physrevapplied.18.054059
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发表时间：
2022-06
影响因子：
4.6
通讯作者：
A. Nikzamir;F. Capolino
中科院分区：
文献类型：
--
作者：
A. Nikzamir;F. Capolino
- 我们提出了一个方案，用于获得高灵敏度的振荡器在耦合谐振器系统与一个例外点的简并（EPD）和一个小的不稳定性。通过使用具有几乎平衡的小信号增益和损耗的两个耦合谐振器来实现具有异常简并的振荡器，所述耦合谐振器由于有源部件的非线性效应而饱和，从而导致对电路的扰动非常敏感的振荡频率。两种情况下进行了研究，与两个并联LC谐振器的平衡小信号增益和损耗，无论是无线耦合的互感或耦合线的电容器。本文从理论和实验上论证了获得二阶EPD振荡器的条件，分析了振荡频率对元件扰动的超灵敏性，包括非对称扰动破坏PT对称性的情况。我们讨论了非线性对振荡器性能的影响，以及所提出的方案如何提高传感器对扰动的灵敏度。与以往的方法相比，我们提出的简并振荡器可以检测电路元件的正或负变化。简并振荡器电路可以在诸如超灵敏传感器、可调谐振荡器和调制器的各种领域中找到应用。
—We propose a scheme for obtaining highly-sensitive oscillators in a coupled-resonator system with an exceptional point of degeneracy (EPD) and a small instability. The oscillator with the exceptional degeneracy is realized by using two coupled resonators with an almost balanced small-signal gain and loss, that saturates due to nonlinear effects of the active component, resulting in an oscillation frequency that is very sensitive to a perturbation of the circuit. Two cases are investigated, with two parallel LC resonators with balanced small-signal gain and loss that are either coupled wirelessly by mutual inductance or coupled-wired by a capacitor. This paper demonstrates theoreti- cally and experimentally the conditions to obtain a second-order EPD oscillator and analyzes the ultrasensitivity of the oscillation frequency to components’ perturbation, including the case of asymmetric perturbation that breaks PT-symmetry. We discuss the effects of nonlinearity on the performance of the oscillator and how the proposed scheme improves the sensing’s sensitivity of perturbations. In contrast to previous methods, our proposed degenerate oscillator can sense positive or negative changes of a circuit component. The degenerate oscillator circuit may find applications in various areas such as ultrasensitive sensors, tunable oscillators and modulators.