Authors: N. Izza, M. Nor, K. Shah, J. Singh, Z. Sauli
Affilation: La Trobe University, Australia
Pages: 169 - 172
Keywords: FBAR, FBAR Filter, Ku-band, MEMS
In this work, the optimisation and analysis of the Ku-band FBAR using 3-D finite element modelling (FEM) is presented. The estimation of material damping coefficients (α and β) using the Akhieser approximation is carried out to estimate more accurate values of the coefficients, thus a more realistic value of Q factor will be achieved. The value of β calculated is 3.84e-14 and the Q factor of 300-330 has been achieved for the Ku-band FBAR. The Ku-band FBAR is designed with the optimum thickness ratio of electrode to the piezoelectric material (tm/tp) to achieve a maximum value of electromechanical coupling coefficient (k2eff). A maximum value of k2eff of 6.47% for series FBAR and 6.51% for shunt FBAR is achieved. This work also presents the design of Ku-band FBAR filter implemented with the optimised Ku-band FBAR by using the ABCD matrix method. The designed Ku-band FBAR filter has the centre frequency of 15.5 GHz, the insertion loss of -3.36dB, out-of-band rejection of -11.90dB and fractional bandwidth of 7.0%. The optimised FBAR filter shows better performance and smaller size when compared with the other FBAR filters and Ku-band filters in literatures [1-5].