Mutual Inductance of Capacitor Low-Pass Filters

This paper describes the magnetic coupling of simple SMD capacitor low-pass filters which is investigated by the method of partial elements (PEEC). Based on analytical equations, the improvement of simple filter structures is possible with the help of the PCB layout only. As has been shown by measurement and simulation, the advanced usage of one and two capacitors allows improvements of up to 20 dB at 1 GHz resulting exclusively from the chosen PCB layout. Moreover, attenuation can be increased up to 42 dB with low-ESL capacitors.