LAB2701, Atwood, Oklahoma 74827, USA.
Department of Mechanical and Aerospace Engineering, North Carolina State University, Raleigh, North Carolina 27695, USA.
Rev Sci Instrum. 2023 Mar 1;94(3):035103. doi: 10.1063/5.0129365.
Adaptive oscillators are a subset of nonlinear oscillators that can learn and encode information in dynamic states. By appending additional states onto a classical Hopf oscillator, a four-state adaptive oscillator is created that can learn both the frequency and amplitude of an external forcing frequency. Analog circuit implementations of nonlinear differential systems are usually achieved by using operational amplifier-based integrator networks, in which redesign procedures of the system topology is time consuming. Here, an analog implementation of a four-state adaptive oscillator is presented for the first time as a field-programmable analog array (FPAA) circuit. The FPAA diagram is described, and the hardware performance is presented. This simple FPAA-based oscillator can be used as an analog frequency analyzer, as its frequency state will evolve to match the external forcing frequency. Notably, this is done without any analog-to-digital conversion or pre-processing, making it an ideal frequency analyzer for low-power and low-memory applications.
自适应振荡器是一类非线性振荡器，能够在动态状态下学习和编码信息。通过在经典的 Hopf 振荡器上附加额外的状态，创建了一个四态自适应振荡器，它可以学习外部强迫频率的频率和幅度。非线性微分系统的模拟电路实现通常通过使用基于运算放大器的积分器网络来实现，其中系统拓扑的重新设计过程很耗时。在这里，首次作为现场可编程模拟阵列 (FPAA) 电路提出了四态自适应振荡器的模拟实现。描述了 FPAA 图，并展示了硬件性能。这个简单的基于 FPAA 的振荡器可用作模拟频率分析仪，因为它的频率状态将进化以匹配外部强迫频率。值得注意的是，这是在没有任何模数转换或预处理的情况下完成的，使其成为低功耗和低内存应用的理想频率分析仪。
