Compact LTCC dual-band bandpass filter using stepped impedance resonators

Abstract

This paper presents a low-temperature co-fired ceramic (LTCC) dual-band bandpass filter with compact size and high selectivity. By using one set of stepped impedance resonators (SIRs), a 2.45/5.2GHz dual band filter is achieved. A novel source-load coupling is induced to generate three transmission zeros (TZs), resulting in high selectivity. The circuit size is 2.8 mm×2.5 mm×0.8 mm. The filter responses are presented to verify the theoretical predications.