The rapid development of communication technologies has created growing demand for high-frequency, miniaturized RF front-end filters. Among available solutions, the lateral excitation film bulk acoustic resonator（XBAR） represents an advanced technology specifically designed for high-frequency applications. Notably, air-gap XBAR structures demonstrate exceptional high-frequency performance owing to their unique architectural design. This study systematically investigates both the fabrication processes and structural characteristics of air-gap XBARs. Through this research, we successfully developed a functional air-gap transverse excitation thin-film bulk acoustic wave filter chip sample. Probe testing revealed that the fabricated device achieves a minimum insertion loss of 1.27 dB, with a passband bandwidth of 808 MHz and a relative passband bandwidth of 15.9%. These experimental results provide valuable reference data for ongoing research into high-frequency, large-bandwidth thin-film bulk acoustic wave filters.