Ultra-high Power Handling Capability Bulk Acoustic Wave Filters using Square Array Topology

The low power handling capability of bulk acoustic wave (BAW) filters restrict their application in high-power communication scenarios, such as base stations and satellites. Conventional methods for enhancing the power handling capability of BAW filters are encumbered by several critical issues, including degradation of the initial filter performance, inefficiencies in filter design, and insufficient conversion efficiency between area and power handling capability. In order to address these challenges, a novel BAW filter design based on a square array topology is proposed. This design integrates current and voltage division techniques while maintaining the area of each resonator in the array consistent with that of the initial resonator. The topology was leveraged to fabricate a BAW filter tailored for the 1.98–2.01 GHz satellite communication band. The fabricated filter exhibits exceptional performance metrics, achieving a minimum insertion loss of -1.9 dB and an out-of-band rejection of -40 dB. It is noteworthy that within a compact chip size of 1.8 × 1.4 mm2, the filter demonstrates an ultra-high power handling capability of 41.1 dBm (12.9 W).