Abstract:

Large inductor value will cause multiple problems such as difficulties in manufacturing and complexity in parasitic parameters while implementing filters using LTCC technology.Due to partialelement equivalentcircuit model (PEEC),delta and starconnected circuit equivalent transformation,three inductors of the second order direct coupling filter can be replaced by two parallel coupling inductors,leading to lowering in the complexity of design,improving in standardization and consistency and smaller packing.Finally a small size intermediate frequency filter of 70 MHz center frequency,14.28% relative bandwidth,1.83 dB insertion loss and less than -15 dB return loss is achieved.

Key words: band pass filters;LTCC;PEEC;inductive coupling