Why Not(ch)?

The paper presents an alternative EMI filtering solution. Drawbacks of low-frequency differential mode filters are discussed and a solution for mitigating given disadvantages is proposed. A need for filter optimization based on a dominant mode of interference and terminating impedances has been addressed, as well as a novel optimization parameter - the applicable frequency band of the filter. Applying a broadband filter to a narrowband interference proved to be an immoderate solution with respect to weight, volume, and price of the filter. On the contrary, the proposed narrowband notch filter, while providing attenuation comparable to a conventional low-pass filter, has significantly smaller weight and volume.