Miniaturized LTCC wideband bandpass filter using lumped-element shunt LC resonators

In this letter, shunt LC resonators realized by multilayer spiral inductors and Metal-Insulator-Metal (MIM) capacitors in parallel connection are proposed to design the wideband bandpass filter (BPF) using Low Temperature Co-fired Ceramic (LTCC) technology. A distinct feature of this filter is the ingenious use of mutual coupling and broadside coupling which are introduced by the close packed elements, so as to achieve the coupling between adjacent resonators. With the assistance of the cross coupling which is implemented by a Z-shaped metal layer, a pair of transmission zeros are produced both above and below the passband.