A qualitative method to verify the presence of parametric oscillations at ${f_{0}}/{2}$ in power amplifiers (PAs) is presented and validated. It relies on the simultaneous application of fundamental and subharmonic tones to trigger possible parametric oscillations and can be implemented in any commercial harmonic balance solver without requiring any external software that may be expensive or however not available to the designer. Wide applicability is guaranteed by the fact that this method does not require access to any internal node of the circuit. In fact, the amplifier is handled as a black-box where only the input and output ports are accessible. The stability check is first demonstrated on a simplified case study and then validated on a real K-band integrated PA, where it correctly reproduces with simulations the parametric oscillations observed by measurements. On the redesigned amplifier, the proposed test predicted the absence of oscillations, which has been confirmed by the experimental characterization.

中文翻译：

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使用谐波平衡求解器识别功率放大器中参数振荡的简单方法

一种定性方法，用于验证在以下位置存在参数振荡 $ {f_ {0}} / {2} $ 介绍并验证了功率放大器（PA）中的功率放大器。它依靠同时应用基本和次谐波音来触发可能的参数振荡，并且可以在任何商用谐波平衡求解器中实现，而无需任何昂贵或无法为设计人员使用的外部软件。该方法不需要访问电路的任何内部节点，从而保证了广泛的适用性。实际上，该放大器被视为一个黑盒，其中只有输入和输出端口可访问。首先在简化的案例研究中证明了稳定性检查，然后在真实的K波段集成PA上进行了验证，并在仿真中正确再现了通过测量观察到的参数振荡。在重新设计的放大器上，