Abstract:This paper describes an imported microcircuit IF filter module. The IF microcircuit module is a kind of composite broadband monolithic crystal filter with the center frequency of 12.1 MHz, 3 dB bandwidth of 240 kHz and its volume is only 35 mm×25 mm×5 mm, which using interpolation structure to improve the performance of the monolithic crystal filters . The experiment proved that the interpolation structure has improved the shape factor, increased the band rejection and the frequency fine tune of the monolithic crystal filter.