Thick film symmetrical EMI LC cells

Abstract

Thick film symmetrical LC cells with two pairs of terminations were printed on alumina using PdAg paste and crossover dielectric. Planar inductors such as meander, spiral, bispiral, and solenoid in plane were distributed over planar capacitors such as sandwich, interdigitated and segmented. Attenuation and Smith charts of symmetrical EMI LC cells were measured on network analyzer in the range of 1 MHz to 3 GHz. Two or three main LC cells were joined in series to sum attenuation. The obtained results were compared mutually, at first, and than with the cubic (chip) EMI LC filters. The obtained EMI noise suppression was similar, but the filter band of thick film LC cells was much wider.