The bulk acoustic wave filter composed of piezoelectric thin film resonators has many features superior to those other small filters such as a surface (SAW) and ceramic filter. As it no fine structure in its electrode design, high Q factor that leads low-loss sharp-cut off characteristics power durability particularly the high-frequency range. Furthermore, potentiality integrated devices on Si substrate. In this paper, we review recent developments resonator world, including our development...

We propose a series of new compositions AlN-based piezoelectric material based on the results first-principles calculation. The composition is expressed by Al1−xN, where elements α and β are selected to maintain charge neutrality host AlN. found that selection Mg2+ for Hf4+ Zr4+ with y = 0.5 show good chemical stability much better properties than pure Our indicate broad compositional freedom improving AlN using co-doping technique.

A bandpass filter using surface acoustic wave (SAW) resonators in a ladder circuit structure for portable telephone systems is reported. For design, simulation tool used to consider the effects of electrodes (their apertures, number paired elements, thickness, and bulk radiation). Filter input output impedance conditions are designed by resonator capacitance match line impedance. The insertion loss stopband rejection values traded off against each other controlled ratio capacitances between...

This paper reports the crystal structures and piezoelectric properties of Mg Zr co-doped AlN (MgZr-doped AlN) thin films. MgZr-doped films on Si (100) substrates were fabricated by using a radio-frequency magnetron reactive cosputtering system. The relations between dopant concentration measured X-ray diffraction, transmission electron microscopy, constant d <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">33</sub> with piezometer investigated....

The first 24 and 30 GHz band thin-film bulk acoustic resonator (FBAR) filters are reported in this paper. were configured with air-gap-type FBARs on a flat silicon substrate. They designed using Butterworth–Van-Dyke (BVD) equivalent circuit considering the linear relationship between resonant frequency, capacitance ratio, loss FBAR. measured characteristics corresponded those of simulation pass-band. center fractional bandwidth, minimum insertion loss, out-of-band suppression 23.8 GHz, 3.4%,...

We have developed an X-band filter utilizing air-gap-type film bulk acoustic resonators (FBARs). The air-gap structure is simple and cost-effective. Results from both simulations experiments demonstrate that a dome-shaped air gap was formed between the substrate surface bottom electrode FBAR possible. can be on flat using stress control of piezoelectric metal films without thick sacrificial layer. As result, fabricated operated successfully with keff2 6.30%, resonance Q 246, antiresonance...

In this paper, we report new piezoelectric materials composed of charge-compensated co-doped (Mg, β) <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</sub> Al xmlns:xlink="http://www.w3.org/1999/xlink">1-x</sub> N (β = Zr or Hf). The effect the dopant element into AlN on chemical stability, crystal structure, and property was determined basis first-principles calculation, theoretical confirmed by experimentally depositing thin films magnesium...

Fujitsu has developed high-performance, miniature aluminum nitride (AlN) thin Film Bulk Acoustic Resonators (FBAR) filters for 5-GHz Wireless Local Area Network (WLAN) applications. Filters with higher frequencies of around 5 GHz and wider bandwidths will be needed in future mobile communication systems. Therefore, we using thin-film Wave (BAW) technology, which shows promise as a possible solution to these frequency There are two issues related the development FBAR filters. The first been...

We have developed a new electrode material, suitable for AlN-based FBARs. The necessary conditions FBAR materials are low density, resistivity, and high acoustic impedance. investigated the influence of on resonant characteristics in FEM simulations experiments. found properties ruthenium (Ru) to be use as In addition, by smoothing surface electrodes, full width at half-maximum (FWHM) X-ray rocking curves AlN films is 2.9/spl deg/ Ru electrodes. using electrodes were an unloaded quality...

This paper describes a circuit model for the analysis of nonlinearity in filters based on radio- frequency (RF) bulk acoustic wave (BAW) resonators. The nonlinear output is expressed by current source connected parallel to linear resonator. Amplitude programmed proportional product currents flowing Thus, performed common analysis, even complex device structures. applied ladder-type RF BAW filter, and dependence discussed. Furthermore, this verified through comparison with experiments.

We describe the development of an air-gap type film bulk acoustic resonator (FBAR) filter fabricated using a thin sacrificed layer on flat substrate. In process we focused reducing cost wafer process. Results from both simulations and experiments demonstrate that dome- shaped air gap was formed between substrate surface bottom electrode FBAR structure possible. Even if is used, can be stress control. Consequently, Q-factor at resonance anti-resonance effective k <sup...

In this paper, we discuss the nonlinear performance difference between surface acoustic wave (SAW) and bulk (BAW) resonators, which are inter-modulation-distortion (IMD) triple-beat (TB) products, indicate importance to reduce even-order nonlinearity of BAW resonator. Then, were able validate accuracy efficiency our proposed simulation technique on devices by comparing with experimental data. We verified that circuit model is a high-performance tool can be used predict device nonlinearities....

In this paper, we discuss the nonlinear performance difference between surface acoustic wave (SAW) and bulk (BAW) resonators, which include intermodulation distortion (IMD) or triple-beat (TB) products, indicate importance of reducing even-order nonlinearities BAW resonators. We were able to validate accuracy efficiency our proposed simulation technique for devices by comparing results with experimental data. verified that circuit model is a high-performance tool can be used predict device...

For portable telephone applications, we improved the power durability of ladder-type filters composed one-port surface acoustic wave (SAW) resonators. In these filters, chip temperature was raised and weak around both cut-off frequencies in transmission characteristics. Power tests a duplexer showed that receiver filter (Rx) which leaked from transmitter one (Tx) weaker than Tx. We therefore studied Rx this work. design, reducing resonator resistance to suppress rise durability. The lifetime...

This paper describes FBAR and SAW resonators which have high-Q factor using unique technology, their applications. A new electrode material suitable for AlN-based FBARs been developed in order to realize low loss. The necessary conditions materials are resistivity high acoustic impedance. It is found the properties of ruthenium (Ru) be use as FBARs. resonant characteristics Ru electrodes indicates Q <inf xmlns:mml="http://www.w3.org/1998/Math/MathML"...

Deterioration of the effective electromechanical coupling factor (K <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">eff</sub> <sup xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> ) upon improving temperature coefficient frequency (TCF) is a serious issue for temperature-compensated bulk acoustic wave (TC-BAW) resonators, because TC-BAW filter applications are restricted to bandpass filters with narrow relative bandwidths under 1.5% in...

The improvement on power durability of SAW filters in order to realize a duplexer is described this study IDT metallization. Compared with the conventional single layer metallizations such as Al-Cu, laminated films are found show higher durability. Many kinds film were tested changing material middle for three layered which top and bottom layers made Al-Cu or pure Al. Among them, two types Al-Cu/Cu/Al-Cu Al/Mg/Al showed best had lifetime 250 times longer than that current film. further...

A bulk acoustic wave filter composed of piezoelectric thin-film resonators has many features superior to those other small filters such as a surface (SAW) and ceramic filter. high-Q factor low loss are big advantages for film resonator (FBAR). The electrode material that is selected very important maintaining appropriate coupling factor. An analysis the effects impedance on AlN-based FBAR performance described. electromechanical (k2) were found be influenced by mainly dominated Young's...

We discuss the effect of aluminum nitride (AlN) film stress on electromechanical coupling coefficient (k <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> ) bulk acoustic resonators (FBAR) based first-principle calculations and experiments. Our indicate that compressive AlN induces expansion c-axis lattice constant affected piezoelectric AlN. found k FBAR estimated using calculation increase with decreasing films. also confirmed from...

This paper describes a design technology of small antenna duplexer, especially package conditions, by using ladder type SAW filters. requires not only optimizing the filter but also electrode materials and which has matching circuitry for duplexer configuration. The was incorporated into microstrip structural pattern is designed onto surface multilayer ceramic package. To avoid deterioration in-band VSWR reflection coefficient stop-band after rotating phase caused pattern, characteristic...

Views Icon Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Twitter Facebook Reddit LinkedIn Tools Reprints and Permissions Cite Search Site Citation A. Nagakubo, H. Ogi, Ishida, M. Hirao, T. Yokoyama, Nishihara; Temperature behavior of sound velocity fluorine-doped vitreous silica thin films studied by picosecond ultrasonics. Journal Applied Physics 7 July 2015; 118 (1): 014307. https://doi.org/10.1063/1.4923353 Download citation file: Ris (Zotero)...

In this paper, we present piezoelectric co-doped (Mg,Hf) <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</sub> Al xmlns:xlink="http://www.w3.org/1999/xlink">1-x</sub> N thin films, where the dopant concentration x is in range of 0-0.13. The films were prepared on Si (100) substrates with a dual magnetron AC power applied between two ring targets. compositions targets pure and Al-Mg-Hf metals. composition was controlled by adjusting DC bias...