Hybrid band-pass filter with integrated passive device and acoustic resonator

Abstract

A novel hybrid band-pass filter is realized using semiconductor integrated hybrid technology, and includes two acoustic resonance units, and one IPD filter unit. The filter unit may be implemented as a high-pass filter, a low-pass filter, or a band-pass filter. The two acoustic resonance units and the IPD filter unit are arranged on a matching substrate, for example, by way of flip-chip technology and welding of electrodes, and a polymer filled shell is formed external to and surrounding the acoustic resonance units and the IPD filter unit to prevent oxidation and to maintain integrity of the weld points. The first acoustic resonance unit is connected with an input terminal of the IPD filter through a matching inductor, an output terminal of the IPD filter is connected with the second acoustic resonance unit through a matching inductor, and finally, the two acoustic resonance units and the IPD filter unit are integrated on the matching substrate. The band-pass filter is characterized by low loss, high suppression, wide passband and high rectangular coefficient, and also has the advantages of small size, high yield, good batch consistency and suitability for batch production.