LTCC dual-band stepped-impedance-stub filter constructed with vertically folded structure

Dual-band filtiers are common in dual-band transceivers, to attenuate interfering signals, and transmit the main signal in the desired passband. Reported is a compact low-temperature co-fired ceramic (LTCC) dual-band filter, constructed with a vertically folded structure and stepped-impedance stubs. The novel vertical interconnection scheme with its multilayered structure reduces the area of the filter by half. A 2.4/5.8 GHz dual-band experimental filter has been designed and assembled to verify the proposed design concept. S-parameter test results demonstrated good agreement between simulation and measurement.