What is the best method to eliminate parasitic oscillations in a power amplifier?

The best method to eliminate parasitic oscillations in a power amplifier is through neutralization. Neutralization involves the use of a feedback mechanism to cancel out the unwanted oscillations that result from parasitic capacitances and inductances in the amplifier circuit. This technique effectively reduces the gain at the frequency of the oscillation, thereby stabilizing the amplifier's operation and preventing these unintended oscillations from occurring.

Parasitic oscillations can arise from various physical characteristics in the circuit, including the layout, the components used, and even the operating frequencies. By introducing specific compensatory measures such as neutralization, the inherent feedback paths that would otherwise amplify these unwanted signals are disrupted, leading to a more stable amplification process.

In contrast, increasing the power supply voltage could exacerbate the issue by increasing the gain of the amplifier and consequently making it more susceptible to oscillations. Replacing the oscillator does not directly address the root causes of parasitic oscillations within the amplifier. Lastly, adding a filter circuit might help to reduce noise or block certain frequencies but does not directly counteract the conditions leading to parasitic oscillations like neutralization does. Thus, neutralization stands out as the most effective method for eliminating these unwanted oscillations in power amplifiers.