"Inductance" is merely a parameter that describes an inductor under ideal DC or low-frequency conditions. Actual inductive components exhibit parasitic capacitance (C_p) and parasitic resistance, which vary depending on factors such as package size, ratings, material properties, and winding density, ultimately affecting the performance of the inductor. Therefore, when selecting an inductor, pay attention to the following points:
- Self-Resonant Frequency (SRF): It must be significantly higher (typically at least twice) than your operating frequency.
- Q Factor: Ensure that the Q factor at your operating frequency is sufficiently high to meet insertion loss and selectivity requirements.
- Rated Current: Avoid magnetic saturation, especially when used in output matching for power amplifiers.
- Package and Size: These affect parasitic effects and circuit board layout.