- Low Pass Filter
A filter that allows direct current and low-frequency signals to pass through while attenuating (unwanted) high-frequency noise.
- Panel Mount Filter
A panel-mounted filter that passes signals from one side of a shielded box (or “Faraday cage”) to the other (which feeds the signal through the panel).
To operate effectively, the input and output of the filter should be shielded from each other, i.e.ideally there should be no holes in the panel.
- Working voltage
Continuous working voltage.
This may span the entire working temperature range.
- Feedthrough Capacitor
The capacitors used in EMI filters are generally ceramic capacitors. Due to their physical structure, such ceramic capacitors are also called feedthrough capacitors.
The self-inductance of feedthrough capacitors is much smaller than that of ordinary capacitors, so the self-resonant frequency is very high. At the same time, the through-core design also effectively prevents high-frequency signals from being directly coupled from the input end to the output end. This combination of low pass and high impedance provides excellent rejection in the 1GHz frequency range.
The simplest feedthrough structure is one (C type) or two capacitors (Pi type) consisting of inner and outer electrodes and ceramics, The capacitance of this capacitor can range from 10pF to 2uF, and the operating voltage can reach 1000VDC. Due to its coaxiality, the tubular feedthrough capacitor will not produce obvious self-resonance even at a frequency of 10GHz.
