Ultra-miniature high-Q filters and duplexers using FBAR technology

Piezoelectric aluminum nitride nanoelectromechanical actuators

“…[9][10][11][12] Out of these two materials, AlN stands out for its high dielectric strength, ease of deposition, and processing ͑involving low temperatures and nontoxic precursors͒, and its potential for integration with CMOS devices. AlN has previously been used for the fabrication of MEMS contour mode filters, 13 film bulk-wave acoustic resonator ͑FBAR͒ filters 14 ͑AlN being the material of choice for commercial FBAR production͒, high frequency resonators, 15 and switches. 9,10 Scaling of piezoelectric transduction to the nanoscale has failed in the past because of degradation of piezoelectric properties due to limited orientation in thin films and increases in internal stresses ͑cracking and excessive deformations in released structures͒.…”

Integration of AlN micromechanical contour-mode technology filters with three-finger dual beam AlN MEMS switches

“…PZT has the disadvantage of not being CMOS compatible and hard to work with. AlN based processes are instead CMOS compatible and AlN is already a proven material for RF applications (see Avago FBAR [13]). In this paper we present the monolithic integration of AlN based contour-mode filters with an AlN based three-finger dual-beam actuation switch (Fig.…”

Active N-path Filters: Theory and Design

“…The basic configuration of a BAW (Bulk Acoustic Wave) resonator is a piezoelectric thin film surrounded by two metal electrodes [43,44,45,46,47,48,49,50,51,52]. Fig.…”

“…2.13 [43]. FBAR resonators can offer Q-factors in the range of 1k [43,44,45,46,47,48,49,50,52,53]. In [43], a duplexer based on FBAR resonators was fabricated working at 1900 MHz (the PCS band), which was 10 times smaller than its off-chip counterpart and it was better than a SAW duplexer in terms of power handling [46,47,48].…”

“…FBAR resonators are extensively used in oscillator design leading to very low power and low phase-noise LO generations [43,44,45,49,53,56,58,59]. In most cases, the FBAR resonators are wire bonded to the transistor chip.…”