Tsai, H.-Y.H.-Y.TsaiRUEY-BEEI WU2021-05-052021-05-052019https://www.scopus.com/inward/record.url?eid=2-s2.0-85063735820&partnerID=40&md5=256ce474e5273ba8ecad1cb90dff89ebhttps://scholars.lib.ntu.edu.tw/handle/123456789/559153This paper proposes a fourth-order Chebyshev tunable bandpass filter by film bulk acoustic resonators (FBAR) with high electromechanical coupling coefficient (kt2). Using coupling capacitors, the tunable FBAR filter is designed by coupling theory of filter design. The resonators are simulated by the MBVD model with series inductor and simplified by parallel RLC model. Tunable capacitors are used to adjust center frequency, coupling coefficient and external quality factor such that the type of filter response can be designed. The tunable filter by high kt2 lead zirconate titanate (PZT) FBAR with 45MHz bandwidth is designed for center frequency ranging from 2.07GHz to 1.80GHz. The insertion loss is 1.46dB to 5dB. The tuning range of tunable filter with <;4dB insertion loss is about 8.2% by high-Q digital capacitors of Q=150.[SDGs]SDG7conference paper10.23919/APMC.2018.86716792-s2.0-85063735820