Download or read book Design and Fabrication of Tunable Thickness Excitation Film Bulk Acoustic Resonators and Stacked Crystal Filters for High Frequency Communication Systems written by Hasnain Lakdawala and published by . This book was released on 1997 with total page 194 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Tuneable Film Bulk Acoustic Wave Resonators written by Spartak Gevorgian and published by Springer Science & Business Media. This book was released on 2013-02-14 with total page 255 pages. Available in PDF, EPUB and Kindle. Book excerpt: To handle many standards and ever increasing bandwidth requirements, large number of filters and switches are used in transceivers of modern wireless communications systems. It makes the cost, performance, form factor, and power consumption of these systems, including cellular phones, critical issues. At present, the fixed frequency filter banks based on Film Bulk Acoustic Resonators (FBAR) are regarded as one of the most promising technologies to address performance -form factor-cost issues. Even though the FBARs improve the overall performances the complexity of these systems remains high. Attempts are being made to exclude some of the filters by bringing the digital signal processing (including channel selection) as close to the antennas as possible. However handling the increased interference levels is unrealistic for low-cost battery operated radios. Replacing fixed frequency filter banks by one tuneable filter is the most desired and widely considered scenario. As an example, development of the software based cognitive radios is largely hindered by the lack of adequate agile components, first of all tuneable filters. In this sense the electrically switchable and tuneable FBARs are the most promising components to address the complex cost-performance issues in agile microwave transceivers, smart wireless sensor networks etc. Tuneable Film Bulk Acoustic Wave Resonators discusses FBAR need, physics, designs, modelling, fabrication and applications. Tuning of the resonant frequency of the FBARs is considered. Switchable and tuneable FBARs based on electric field induced piezoelectric effect in paraelectric phase ferroelectrics are covered. The resonance of these resonators may be electrically switched on and off and tuned without hysteresis. The book is aimed at microwave and sensor specialists in the industry and graduate students. Readers will learn about principles of operation and possibilities of the switchable and tuneable FBARs, and will be given general guidelines for designing, fabrication and applications of these devices.

Download or read book Multilayer Integrated Film Bulk Acoustic Resonators written by Yafei Zhang and published by Springer Science & Business Media. This book was released on 2012-08-28 with total page 159 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mulilayer Integrated Film Bulk Acoustic Resonators mainly introduces the theory, design, fabrication technology and application of a recently developed new type of device, multilayer integrated film bulk acoustic resonators, at the micro and nano scale involving microelectronic devices, integrated circuits, optical devices, sensors and actuators, acoustic resonators, micro-nano manufacturing, multilayer integration, device theory and design principles, etc. These devices can work at very high frequencies by using the newly developed theory, design, and fabrication technology of nano and micro devices. Readers in fields of IC, electronic devices, sensors, materials, and films etc. will benefit from this book by learning the detailed fundamentals and potential applications of these advanced devices. Prof. Yafei Zhang is the director of the Ministry of Education’s Key Laboratory for Thin Films and Microfabrication Technology, PRC; Dr. Da Chen was a PhD student in Prof. Yafei Zhang’s research group.

Download or read book Acquisition List written by University of Hawaii at Manoa. Library. Hawaiian Collection and published by . This book was released on 1997 with total page 144 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Acoustic Wave and Electromechanical Resonators written by Humberto Campanella and published by Artech House. This book was released on 2010 with total page 364 pages. Available in PDF, EPUB and Kindle. Book excerpt: This groundbreaking book provides you with a comprehensive understanding of FBAR (thin-film bulk acoustic wave resonator), MEMS (microelectomechanical system), and NEMS (nanoelectromechanical system) resonators. For the first time anywhere, you find extensive coverage of these devices at both the technology and application levels. This practical reference offers you guidance in design, fabrication, and characterization of FBARs, MEMS and NEBS. It discusses the integration of these devices with standard CMOS (complementary-metal-oxide-semiconductor) technologies, and their application to sensing and RF systems. Moreover, this one-stop resource looks at the main characteristics, differences, and limitations of FBAR, MEMS, and NEMS devices, helping you to choose the right approaches for your projects. Over 280 illustrations and more than 130 equations support key topics throughout the book.

Download or read book Switchable and Tunable Bulk Acoustic Wave Devices Based on Ferroelectric Material written by Almonir Abdulgader Mansour and published by . This book was released on 2017 with total page 203 pages. Available in PDF, EPUB and Kindle. Book excerpt: The explosive development of personal communications systems, navigation, satellite communications as well as personal computer and data processing systems together with the constant demand for higher speeds and larger bandwidths has driven fabrication technology to its limits. This, in turn, necessitates the development of novel functional materials for the fabrication of devices with superior performance and higher capacity at reduced manufacturing costs. Ferroelectric materials such as barium strontium titanate (BST) and strontium titanium oxide (STO) have received more attention by researchers and industry because of their field-induced piezoelectric property. This property gives these types of ferroelectric materials the ability to be switchable and tunable in the presence of an electric field. These features have allowed the ferroelectric materials to be used in many applications such as non-volatile memory and DRAMs, sensors, pyroelectric detectors, and tunable microwave devices. Therefore, with the ever increasing complexity in RF front-end receivers, and the demand for services (which in turn requires more functionalities), ferroelectric bulk acoustic wave (BAW) resonators and filters that are intrinsically switchable and promise to reduce the size and complexity of component parts. In this work, we present the design, fabrication and experimental evaluation of switchable and tunable thin film bulk acoustic wave (BAW) resonators, filters and duplexers for radio frequency (RF) applications. The switchability and tunability of these devices come from utilizing the electrostrictive effect of ferroelectric materials such as barium strontium titanate (BST) with the application of an external DC-bias voltage. The BAW resonators, filters and duplexers in this work were fabricated on different substrates as solidly mounted resonator (SMR) structure with number of periodic layers of silicon dioxide and tantalum oxide as a Bragg reflector in order to acoustically isolate the resonator from the damping effect of the substrate, enhancing the quality factor and temperature compensation.

Download or read book Design and Implementation of Solid solid Phononic Crystal Structures in Lateral Extensional Thin film Piezoelectric on Silicon Micromechanical Resonators written by Abdulrahman Alsolami and published by . This book was released on 2020 with total page 85 pages. Available in PDF, EPUB and Kindle. Book excerpt: Achieving high quality factor in MEMS resonator devices is a critical demand for today’s wireless communication and sensing technologies. In order to reach this goal, several dedicated prior works have been conducted based on published literature at different frequency ranges. Particularly, piezoelectrically transduced resonators, which are widely deployed in commercial wireless communication systems, could benefit from greatly improved qualify factor. So far, their development has evolved from thin film bulk acoustic resonators (FBAR’s) using surface attached piezoelectric thin-film transducers with moderate Q factors to high Q resonators equipped with a side-supporting tether (anchor) attached vibrating resonators that allow the devices to operate at very high frequency (VHF) and ultra-high frequency (UHF) ranges.This dissertation presents a newly developed fabrication methodology to replace existing expensive SOI technologies with much cheaper single crystalline wafers using a modified Single-Crystalline Reactive Etched and Metallization (SCREAM) process. Piezoelectrically transduced MEMS resonators have been fabricated at USF cleanroom facility, which have been designed and tested successfully in air with a quality factor of 1,528 and an insertion loss of -32.1 dB for a disk shaped resonators. A quality factor of 1,013 along with an insertion loss of -19 dB have been achieved for a rectangular plate resonator. In these devices, varied silicon layer thickness ranging from submicrons to tens of microns from a single layer were achieved as opposed to an uniform thickness of the device layer across the silicon-on-insulator (SOI) wafers, allowing device batch fabrication while maintaining the same number of photolithography steps. Resonators with varied Si resonator structure layer thickness have been implemented and studied in terms of motional resistance (Rm), quality factor (Q) and resonance frequency.To our best knowledge, this work has pioneered the implementation of soild/soild phononic crystals (PnCs) in fully suspended, lateral extensional and contour mode bulk acoustic wave (BAW) resonators. The in-house fabrication of the PnCs was performed on silicon-on-insulator (SOI) substrate. Silicon and tungsten were chosen as alternated layers for PnCs with a 4.5 ratio of acoustic impedance mismatch between the two chosen solid materials. The analysis of solid/solid PnCs bandgap is also conducted for determining the frequency regime, where no phonons exist. PnCs are strategically designed with piezoelectric transduction mechanism to operate within the phononic bandgap regime. Finite Element method (FEM) is also performed to investigate PnCs behavior in acoustic wave rejection, in which it was evaluated to be ~11 dB rejection per crystal.Lastly, the fully released thin-piezo on silicon (TPoS) resonators in this work have been fabricated, characterized and modeled. The work of fabricating fully released BAW resonators with embedded PnCs one of the pioneering work of solid/solid PnCs in the MEMS resonator field. The electrical equivalent circuit parameters of the devices were extracted and the quality factors for these devices have shown 7-10 times enhancement as compared to counterparts without PnCs.

Download or read book Multilayer Integrated Film Bulk Acoustic Resonators written by Yafei Zhang and published by . This book was released on 2013 with total page 152 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Fabrication Development and Analysis of Film Bulk Acoustic Resonators on Flexible Polymer Substrates written by Ghazal Hakemi and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: It is the focus of this project to explore the possibility of achieving Radio Fre?quency (RF) micro-devices on flexible polymer substrates. To this end standard MEMS fabrication methods have been tailored to allow the integration of func?tional materials and device patterning for production of RF MEMS devices with flexible organic substrates. Material quality, device yield, performance and re-liability are critical aspects of our study. The project encompasses the use of a direct integration method for the creation of Film Bulk Acoustic Resonators (FBARs) on Liquid Crystal Polymer (LCP) substrates. An FBAR is a passive component used for resonance and filtering purposes. Its production on organic substrates would lead to a number of ad-vantages including: overall cost savings, size reduction and ability of the device to be directly integrated on the printed circuit board (PCB) front-end with the other essential components (i.e. antenna) without the use of wiring and inter-connections. New fabrication process flows have been developed to allow the creation of FBAR microwave devices on LCP. First of all pre-processing of the polymer substrate is carried out to make it rigid and smooth. Substrate smoothness and stiffness are necessary in order to obtain functioning devices and for the substrate to comply to the standard fabrication methods. Rigidity is achieved through a backing method whereby silicon or glass are attached to LCP with an intermediate adhesive layer. The best way to achieve smoothness was found to be Chemical Mechanical Polishing (CMP). Standard fabrication techniques were then employed to deposit the metal and piezoelectric material and pattern them. Both bulk and surface micromachining were used and, in some cases, tailored to suit the new substrates (LCP) tolerance limits (such as temperature and flexibility). Zinc Oxide (ZnO) piezoelectric is the preferred functional material and it is chosen due to its relatively low deposition temperature re?quirements (below 300C) and its high frequency characteristics. The creation of a front-to-back processed FBAR on LCP is successfully carried out at relatively low temperatures since the Zinc oxide (ZnO) functional mate?rial is proven to yield good crystallinity at a deposition temperature of 100C and also because micromachining temperatures do not generally exceed 115C. The final device is characterized through RF measurements, compared with sim?ulations and standard FBARs and the polymer/ceramic integration reliability for device creation is briefly addressed. In conclusion FBARs are successfully created on LCP with only minor compli?cations related to LCP surface roughness and RIE etch of the polymer. The project lays promising prospects for RF MEMS devices on compliant organic substrates.

Download or read book Temperature Compensated and High Q Piezoelectric Aluminum Nitride Lamb Wave Resonators for Timing and Frequency Control Applications written by Chih-Ming Lin and published by . This book was released on 2013 with total page 384 pages. Available in PDF, EPUB and Kindle. Book excerpt: The explosive development of wireless and mobile communication systems has lead to rapid technology innovation in component performance, complementary metal-oxide semiconductor (CMOS) compatible fabrication techniques, and system improvement to satisfy requirements for faster signal processing, cost efficiency, chip miniaturization, and low power consumption. The demands for the high-performance communication systems whose fundamentals are precise timing and frequency control have driven the current research interests to develop advanced reference oscillators and radio frequency (RF) bandpass filters. In turn a promising microelectromechanical systems (MEMS) resonator technology is required to achieve the ultimate goal. That is, micromechanical vibrating resonators with high quality factor (Q) and good frequency-temperature stability at high series resonance frequency (fs) are the required fundamental components for a high-performance wireless communication system. Recently, Lamb wave mode propagating in piezoelectric thin plates has attracted great attention for designs of the electroacoustic resonators since it combines the advantages of bulk acoustic wave (BAW) and surface acoustic wave (SAW): high phase velocity and multiple frequency excitation by an interdigital transducer (IDT). More specifically, the Lamb wave resonator (LWR) based on an aluminum nitride (AlN) thin film has attracted many attentions because it can offer the high resonance frequency, small temperature-induced frequency drift, low motional resistance, and CMOS compatibility. The lowest-order symmetric (S0) Lamb wave mode propagation in the AlN thin plate is particularly preferred because it exhibits a phase velocity close to 10,000 m/s, a low dispersive phase velocity characteristic, and a moderate electromechanical coupling coefficient. However, the uncompensated AlN LWR shows a first-order temperature coefficient of frequency (TCF) of approximately -25 ppm/C. This level of the temperature stability is unsuitable for any timing application. In addition, the Q of the AlN LWR is degraded to several hundred while the IDT finger width is downscaled to a nanometer scale to raise the resonance frequency up to a few GHz. This dissertation presents comprehensive analytical and experimental results on a new class of temperature-compensated and high-Q piezoelectric AlN LWRs. The temperature compensation of the AlN LWR using the S0 Lamb wave mode is achieved by adding a layer of silicon dioxide (SiO2) with an appropriate thickness ratio to the AlN thin film, and the AlN/SiO2 LWRs can achieve a low first-order TCF at room temperature. Based on the multilayer plate composed of a 1-um-thick AlN film and a 0.83-um-thick SiO2 layer, a temperature-compensated LWR operating at a series resonance frequency of 711 MHz exhibits a zero first-order TCF and a small second-order TCF of -21.5 ppb/C^2 at its turnover temperature, 18.05 C. The temperature dependence of fractional frequency variation is less than 250 parts per million (ppm) over a wide temperature range from -55 to 125 C. In addition to the temperature compensation at room temperature, the thermal compensation of the AlN LWRs is experimentally demonstrated at high temperatures. By varying the normalized AlN and SiO2 thicknesses to the wavelength, the turnover temperature can be designed at high temperatures and the AlN LWRs are temperature-compensated at 214, 430, and 542 C, respectively. The temperature-compensated AlN/SiO2 LWRs are promising for a lot of applications including thermally stable oscillators, bandpass filters, and sensors at room temperature as well as high temperatures. The influences of the bottom electrode upon the characteristics of the LWRs utilizing the S0 Lamb wave mode in the AlN thin plate are theoretically and experimentally studied. Employment of a floating bottom electrode for the LWR reduces the static capacitance in the AlN membrane and accordingly enhances the effective coupling coefficient. The floating bottom electrode simultaneously offers a large coupling coefficient and a simple fabrication process than the grounded bottom electrode but the transduction efficiency is not sacrificed. In contrast to those with the bottom electrode, an AlN LWR with no bottom electrode shows a high Q of around 3,000 since it gets rid of the electrical loss in the metal-to-resonator interface. In addition, it exhibits better power handling capacity than those with the bottom electrode since less thermal nonlinearity induced by the self-heating exists in the resonators. In order to boost the Q, a new class of the AlN LWRs using suspended convex edges is introduced in this dissertation for the first time. The suspended convex edges can efficiently reflect the Lamb waves back towards the transducer as well as confine the mechanical energy in the resonant body. Accordingly the mechanical energy dissipation through the support tethers is significantly minimized and the Q can be markedly enhanced. More specifically, the measured frequency response of a 491.8-MHz LWR with suspended biconvex edges yields a Q of 3,280 which represents a 2.6x enhancement in Q over a 517.9-MHz LWR based on the same AlN thin plate but with the suspended flat edges. The suspended convex edges can efficiently confine mechanical energy in the LWR and reduce the energy dissipation through the support tethers without increasing the motional impedance of the resonator. In addition, the radius of curvature of the suspended convex edges and the AlN thickness normalized to the wavelength can be further optimized to simultaneously obtain high Q, low motional impedance, and large effective coupling coefficient. To further enhance the Q of the LWR, a composite plate including an AlN thin film and an epitaxial cubic silicon carbide (3C-SiC) layer is introduced to enable high-Q and high-frequency micromechanical resonators utilizing high-order Lamb wave modes. The use of the epitaxial 3C-SiC layer is attractive as SiC crystals have been theoretically proven to have an exceptionally large fs and Q product due to its low acoustic loss characteristic at microwave frequencies. In addition, AlN and 3C-SiC have well-matched mechanical and electrical properties, making them a suitable material stack for the electroacoustic resonators. The epitaxial 3C-SiC layer not only provides the micromechanical resonators with a low acoustic loss layer to boost their Q but also enhances the electromechanical coupling coefficients of some high-order Lamb waves in the AlN/3C-SiC composite plate. A micromachined electroacoustic resonator utilizing the third quasi-symmetric (QS3) Lamb wave mode in the AlN/3C-SiC composite plate exhibits a Q of 5,510 at 2.92 GHz, resulting in the highest fs and Q product, 1.61x10^13 Hz, among suspended piezoelectric thin film resonators to date.

Download or read book Design Fabrication and Characterization of Beam Supported Aluminum Nitride Thin Film Bulk Acoustic Resonators written by Lori Ann Callaghan and published by . This book was released on 2005 with total page 340 pages. Available in PDF, EPUB and Kindle. Book excerpt: Micro-mechanical filters comprised of bulk acoustic resonators are being fabricated and studied as a solution to the demands for low power consumption, high functionality devices in the telecommunication industry. A novel, suspended thin Film Bulk Acoustic wave Resonator (SFBAR) has been fabricated using an aluminum nitride film sputtered directly on a 100 silicon substrate. The suspended membrane design uses thin beams to support, as well as electrically connect, the resonator. The SFBAR has been fabricated by combining both thin film processing and bulk silicon micro machining. The AlN was etched in an Inductively Coupled Plasma (ICP) chlorine etch, using titanium dioxide as the masking material. A silicon Deep Reactive Ion Etch (DRIE) was used to create an open ended air cavity with a novel circular shape. A representative resonator, designated here as sample W9HS8 resonator 10018, was characterized with a Quality Factor values at resonance and anti-resonance of 68 and 151,

Download or read book Lateral field excitation Film Bulk Acoustic Wave Resonator for High Frequency Wireless Communications written by Woo Wai Lau and published by . This book was released on 1996 with total page 104 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Multilayer Integrated Film Bulk Acoustic Resonators written by Springer and published by . This book was released on 2012-08-29 with total page 164 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Integrated Ring Resonators written by Dominik G. Rabus and published by Springer. This book was released on 2007-04-26 with total page 270 pages. Available in PDF, EPUB and Kindle. Book excerpt: The optical filter is resonator based. The required passband shape of ring resonator-filters can be custom designed by the use of configurations of various ring coupled resonators. This book describes the current state-of-the-art on these devices. It provides an in-depth knowledge of the simulation, fabrication and characterization of ring resonators for use as example filters, lasers, sensors.

Download or read book High Frequency Thin film Bulk Acoustic Wave Resonators for Gas and Bio analytical Applications written by G. M. Ashley and published by . This book was released on 2005 with total page 380 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Simulation and Fabrication of Thin Film Bulk Acoustic Wave Resonator Project Supported by the National Natural Science Foundation of China Nos 61274119 61306141 61335008 and the Natural Science Foundation of Jiangsu Province No BK20131099 written by and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: In this paper, we present the simulation and fabrication of a thin film bulk acoustic resonator (FBAR). In order to improve the accuracy of simulation, an improved Mason model was introduced to design the resonator by taking the coupling effect between electrode and substrate into consideration. The resonators were fabricated by the eight inch CMOS process, and the measurements show that the improved Mason model is more accurate than a simple Mason model. The Q s ( Q at series resonance), Q p ( Q at parallel resonance), Q max and k t 2 of the FBAR were measured to be 695, 814, 1049, and 7.01% respectively, showing better performance than previous reports.

Download or read book Thin Film Bulk Acoustic Wave Devices written by Tuomas Pensala and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Thin film bulk acoustic wave (BAW) resonators and filters operating in the GHz range are used in mobile phones for the most demanding filtering applications and complement the surface acoustic wave (SAW) based filters. Their main advantages are small size and high performance at frequencies above 2 GHz. This work concentrates on the characterization, performance optimization, and modelling techniques of thin film BAW devices. Laser interferometric vibration measurements together with plate wave dispersion modeling are used to extract the full set of elastic material parameters for sputter deposited ZnO, demonstrating a method for obtaining material data needed for accurate simulation of the devices. The effectiveness of the acoustic interference reflector used to isolate the vibration from the substrate is studied by 1-D modeling, 2-D finite element method and by electrical and laser interferometric measurements. It is found that the Q-value of reflector-based BAW resonators operating at 2 GHz is limited to approximately 2000 by mechanisms other than leakage through the reflector. Suppression of spurious resonances in ZnO resonators is studied in depth by modeling and measurements. It is verified that the approximate mode orthogonality is behind the suppression in boundary frame type ZnO devices operating in the piston mode, but also another narrow band mode suppression mechanism is found. A plate wave dispersion based 2-D simulation scheme for laterally acoustically coupled BAW resonator filters is developed and employed in designing of experimental devices, which show both good agreement with the model predictions and a remarkable 4.9 % relative bandwidth.