Stability Analysis and Design Criteria of Paralleled-Device Power Amplifiers Under Large-Signal Regime

Time-Domain Analysis of RF and Microwave Autonomous Circuits by Vector Fitting-Based Approach

“…It is important to remark that, in principle, a similar spectrum could be obtained also with a frequency-domain analysis. However, especially for autonomous signals, a rough estimation of the oscillation frequency should be a-priori available [16], [17] or the use of particular probes is required, such as auxiliary generators as perturbation of the circuit [4]. On the contrary, the transient behaviour cannot be investigated with a frequency-domain analysis, while it can be easily analyzed with the proposed approach.…”

New Stabilization Technique to Prevent Parametric Oscillations in a 35 W C-Band Algan/Gan Mmic High Power Amplifier

“…As aforementioned, the conventional method to detect parametric oscillations is to calculate the zero-poles of the system transfer function. However, this approach, as well as other reported approaches such as Nyquist criterion [25,26], floquet analysis [27], and finding the equivalent conversion matrix of the response to small perturbations [28] are not straightforward and requires substantial processing time. Therefore, an efficient and easy method is proposed in this paper to predict such oscillations.…”

Effective time‐domain approach for the assessment of the stability characteristics and other non‐linear effects of RF and microwave circuits

“…To solve this issue some dedicated approaches for the stability analysis in the frequency-domain have been already proposed in the literature: for example based on the use of an auxiliary generator (AG) [1,3], on pole/zero analysis [4] or on the conversion matrix calculation [5][6][7]. However, all of them require some compromise: in case of the AG technique [3], for instance, it is assumed that a spurious signal is present and that a rough estimation of its frequency is already available.…”

“…However, all of them require some compromise: in case of the AG technique [3], for instance, it is assumed that a spurious signal is present and that a rough estimation of its frequency is already available. In particular, the validity of the approach [4] is limited by the reliability of the identification of the rational function in the frequency domain and its extrapolation to the Laplace domain; while, the technique [6,7] requires a dense discretisation of the frequency-domain transfer function to evaluate the instability and verify the oscillation.…”

“…The main advantage of the proposed method is its capability to analyse directly in the time-domain any RF and microwave circuit, allowing one to obtain an exhaustive description of the behaviour of the circuits, as typical of low-frequency analysis. Hence, a complete and accurate non-linear stability analysis can be carried out, overcoming the limits of frequency domain-based approaches operating at steady-state [3,4,6,7]. At first, the circuit under study is divided into a linear and passive part (including any distributed or lumped elements) and a non-linear one (formed by the active elements).…”