Flexible Film Bulk Acoustic Wave Filters toward Radiofrequency Wireless Communication

• DOI: 10.1002/smll.201703644
• Publication Date: 2018-03-31T05:23:45Z
• Authors: Yuan Jiang; Yuan Zhao; Lin Zhang; Bohua Liu; Quanning Li; Menglun Zhang; Wei Pang
• Keywords: Bend radius; Passband; Electronic filter

This paper presents a flexible radiofrequency filter with central frequency of 2.4 GHz based on film bulk acoustic wave resonators (FBARs). The consists five air-gap type FBARs, each comprised an aluminum nitride piezoelectric thin sandwiched between two thin-film electrodes. By transfer printing the inorganic structure from silicon wafer to ultrathin polyimide substrate, high electrical performance and mechanical flexibility are achieved. has peak insertion loss -1.14 dB, 3 dB bandwidth 107 MHz, temperature coefficient -27 ppm °C-1 . passband roll-off characteristics comparable silicon-based commercial products. No degradation failure occur under bending tests radius 2.5 mm or after 100 cycles. FBAR filters believed be promising candidates for future wireless communication systems.