DCS Tx filters using AlN resonators with Iridium electrodes

M. Clement , E. Iborra , J. Olivares (1, 2) , N. Rimmer , Sylvain Giraud (3, 4) , Stéphane Bila (4) , A. Reinhardt (5)

1 CMAM - Centro de Micro-análisis de Materiales
2 CSIC - Instituto de Optica
3 SRMA - Service des Recherches Métallurgiques Appliquées
4 MINACOM
5 CEA-LETI - Commissariat à l'énergie atomique et aux énergies alternatives - Laboratoire d'Electronique et de Technologie de l'Information

In this paper we present the design, fabrication technology, and characterization of BAW filters for the Digital Cellular System (DCS) Tx-band at 1.75 GHz. The filters are fabricated with AlN-based solidly mounted resonators (SMR) using iridium electrodes, in an attempt to increase the effective electromechanical coupling factor of the BAW devices and achieve the bandwidth requirements of DCS filters. The design and optimization of the filters is performed with a simulation tool that uses a circuit model to compute the filter frequency response. Tx filters with balanced inputs and outputs and different topologies are designed and fabricated. The experimental filter response is compared with the simulations to determine the suitability of each design. DCS bandwidth requirements are fulfilled by using Ir/AlN/Ir stacks.

Mots clés: III-V semiconductors; UHF filters; acoustic resonator filters; aluminium compounds; band-pass filters; bulk acoustic wave device; electrode; electromechanical effects; iridium; metal-semiconductor-metal structures; wide band gap semiconductors

Domaines: Electronique

M. Clement, E. Iborra, J. Olivares, N. Rimmer, Sylvain Giraud, et al.. DCS Tx filters using AlN resonators with Iridium electrodes. IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control, 2010, 57 (3), pp.518-523. ⟨10.1109/TUFFC.2010.1442⟩. ⟨hal-00583445⟩