Design of an Rf Baw Resonator

Band pass filters for microwave frequencies realized with thin film bulk acoustic wave resonators (FBAR) are a promising alternative to current dielectric or surface acoustic wave filters for use in mobile telecommunication applications. With equivalent performance FBAR filters are significantly smaller than dielectric filters and allow for a larger power Operation than SAW filters . In addition FBARs offer the possibility of on-chip integration which will result in substantial volume and cost reduction. First part of the thesis consists of an overview of different types of resonators and their advantages and disadvantages, followed which the design of film bulk acoustic wave resonator (FBAR) and its characterization . Second part of thesis consists of the design of ladder filter from the designed series and shunt resonators and its characterization

Low-thickness high-quality aluminum nitride films for super high frequency solidly mounted resonators

We investigate the sputter growth of very thin aluminum nitride (AlN) films on iridium electrodes for electroacoustic devices operating in the super high frequency range. Superior crystal quality and low stress films with thicknesses as low as 160 nm are achieved after a radio frequency plasma treatment of the iridium electrode followed by a two-step alternating current reactive magnetron sputtering of an aluminum target, which promotes better conditions for the nucleation of well textured AlN films in the very first stages of growth. Solidly mounted resonators tuned around 8 GHz with effective electromechanical coupling factors of 5.8% and quality factors Q up to 900 are achieved

Programmable Microwave Devices (PMDs) based on Liquid Metal

This thesis presents microwaves device which we term a programmable microwave device (PMD). This thesis presents building block elements (BBEs)/PMDs which can realize functional and parametric reconfiguration. This thesis also discusses how to implement Gallium-based liquid metal in a reconfigurable circuit/antenna. Two works were finished and presented in this thesis. The first work presented a BBE and a PMD that can realize the functional reconfiguration. The proposed BBE/PMD can alter its function between non radiating (resonator/filter) mode and radiating (antenna) mode. The proposed BBE/ PMD realizes functional reconfiguration with the aid of liquid metal (LM). The proposed single BBE operates in resonator mode when the fluidic channels are filled with liquid metal. Whereas it operates in antenna mode when the fluidic channels are emptied of liquid metal. When several BBEs are cascaded, they form a PMD. A PMD can realize filter mode operation when the fluidic channels are filled with liquid metal or antenna mode operation when liquid metal is withdrawn. In this work, an easy approach of 2D-shaping LM was also introduced. This approach allows 2D-shaped LM for being used in realizing reconfiguration. When operating in the antenna mode the proposed PMDs provides a measured peak realized gain of 7.23 dBi and a simulated total efficiency of 84%. When operating in the filter mode the proposed PMDs provides a band pass response and exhibits a maximum insertion loss of 1.9 dB, within the passband. The filters have a 10 dB return loss bandwidth of 340 MHz ranges from 2.28 GHz to 2.62 GHz. The second work presents an operating frequency reconfigurable antenna mode BBE, which realizes a wide operating frequency reconfiguring range with the aid of liquid metal. The capability of LM could have a significant impact on reconfigure capability of the proposed PMD. We firstly designed and manufactured a hardwired version of operating frequency reconfigurable antenna mode BBE. After we verified the measurement results of hardwired antenna mode BBE, we 3D-printed the fluidic channels using Polylactic acid (PLA). LM can be filled into the 3D-printed fluidic channels with a changeable length which tunes the operating frequency of the antenna mode BBE. The measurement results of the operating frequency reconfigurable antenna mode BBE agree with the simulation results, verifying the capability of this antenna mode BBE

RECONFIGURABLE AND WIDEBAND SAW RESONATOR-BASED FILTERS & CMOS BANDPASS FILTERS FOR WIRELESS COMMUNICATION SYSTEM

Ph.DDOCTOR OF PHILOSOPH

Lithium niobate RF-MEMS oscillators for IoT, 5G and beyond

This dissertation focuses on the design and implementation of lithium niobate (LiNbO3) radiofrequency microelectromechanical (RF-MEMS) oscillators for internet-of-things (IoT), 5G and beyond. The dissertation focuses on solving two main problems found nowadays in most of the published works: the narrow tuning range and the low operating frequency (sub 3 GHz) acoustic oscillators currently deliver. The work introduced here enables wideband voltage-controlled MEMS oscillators (VCMOs) needed for emerging applications in IoT. Moreover, it enables multi-GHz (above 8 GHz) RF-MEMS oscillators through harnessing over mode resonances for 5G and beyond. LiNbO3 resonators characterized by high-quality factor (Q), high electromechanical coupling (kt2), and high figure-of-merit (FoMRES= Q kt2) are crucial for building the envisioned high-performance oscillators. Those oscillators can be enabled with lower power consumption, wider tuning ranges, and a higher frequency of oscillation when compared to other state-of-the-art (SoA) RF-MEMS oscillators. Tackling the tuning range issue, the first VCMO based on the heterogeneous integration of a high Q LiNbO3 RF-MEMS resonator and complementary metal-oxide semiconductor (CMOS) is demonstrated in this dissertation. A LiNbO3 resonator array with a series resonance of 171.1 MHz, a Q of 410, and a kt2 of 12.7% is adopted, while the TSMC 65 nm RF LP CMOS technology is used to implement the active circuitry with an active area of 220×70 µm2. Frequency tuning of the VCMO is achieved by programming a binary-weighted digital capacitor bank and a varactor that are both connected in series to the resonator. The measured best phase noise performances of the VCMO are -72 and -153 dBc/Hz at 1 kHz and 10 MHz offsets from 178.23 and 175.83 MHz carriers, respectively. The VCMO consumes a direct current (DC) of 60 µA from a 1.2 V supply while realizing a tuning range of 2.4 MHz (~ 1.4% tuning range). Such VCMOs can be applied to enable ultralow-power, low phase noise, and wideband RF synthesis for emerging applications in IoT. Moreover, the first VCMO based on LiNbO3 lateral overtone bulk acoustic resonator (LOBAR) is demonstrated in this dissertation. The LOBAR excites over 30 resonant modes in the range of 100 to 800 MHz with a frequency spacing of 20 MHz. The VCMO consists of a LOBAR in a closed-loop with two amplification stages and a varactor-embedded tunable LC tank. By the bias voltage applied to the varactor, the tank can be tuned to change the closed-loop gain and phase responses of the oscillator so that Barkhausen’s conditions are satisfied for the targeted resonant mode. The tank is designed to allow the proposed VCMO to lock to any of the ten overtones ranging from 300 to 500 MHz. These ten tones are characterized by average Qs of 2100, kt2 of 1.5%, FoMRES of 31.5 enabling low phase noise, and low-power oscillators crucial for IoT. Owing to the high Qs of the LiNbO3 LOBAR, the measured VCMO shows a close-in phase noise of -100 dBc/Hz at 1 kHz offset from a 300 MHz carrier and a noise floor of -153 dBc/Hz while consuming 9 mW. With further optimization, this VCMO can lead to direct RF synthesis for ultra-low-power transceivers in multi-mode IoT nodes. Tackling the multi-GHz operation problem, the first Ku-band RF-MEMS oscillator utilizing a third antisymmetric overtone (A3) in a LiNbO3 resonator is presented in the dissertation. Quarter-wave resonators are used to satisfy Barkhausen’s oscillation conditions for the 3rd overtone while suppressing the fundamental and higher-order resonances. The oscillator achieves measured phase noise of -70 and -111 dBc/Hz at 1 kHz and 100 kHz offsets from a 12.9 GHz carrier while consuming 20 mW of dc power. The oscillator achieves a FoMOSC of 200 dB at 100 kHz offset. The achieved oscillation frequency is the highest reported to date for a MEMS oscillator. In addition, this dissertation introduces the first X-band RF-MEMS oscillator built using CMOS technology. The oscillator consists of an acoustic resonator in a closed loop with cascaded RF tuned amplifiers (TAs) built on TSMC RF GP 65 nm CMOS. The TAs bandpass response, set by on-chip inductors, satisfies Barkhausen's oscillation conditions for A3 only. Two circuit variations are implemented. The first is an 8.6 GHz standalone oscillator with a source-follower buffer for direct 50 Ω-based measurements. The second is an oscillator-divider chain using an on-chip 3-stage divide-by-2 frequency divider for a ~1.1 GHz output. The standalone oscillator achieves measured phase noise of -56, -113, and -135 dBc/Hz at 1 kHz, 100 kHz, and 1 MHz offsets from an 8.6 GHz output while consuming 10.2 mW of dc power. The oscillator also attains a FoMOSC of 201.6 dB at 100 kHz offset, surpassing the SoA electromagnetic (EM) and RF-MEMS based oscillators. The oscillator-divider chain produces a phase noise of -69.4 and -147 dBc/Hz at 1 kHz and 1 MHz offsets from a 1075 MHz output while consuming 12 mW of dc power. Its phase noise performance also surpasses the SoA L-band phase-locked loops (PLLs). The demonstrated performance shows the strong potential of microwave acoustic oscillators for 5G frequency synthesis and beyond. This work will enable low-power 5G transceivers featuring high speed, high sensitivity, and high selectivity in small form factors

High-Performance Reconfigurable Piezoelectric Resonators and Filters for RF Frontend Applications

A conventional RF frontend module consists of many filters where each filter is allocated for a specific frequency band. These filters are connected through multiplexing switch networks to support multi-band wireless standards. Using an individual filter for each frequency band increases the module size, power consumption and cost. Therefore, implementation of reconfigurable filters that can operate at different frequency bands while maintaining key RF performance requirements such as low insertion loss, good linearity and power handling is necessary for manufacturing of future RF frontends. Acoustic wave resonators based on piezoelectric devices such as Surface Acoustic Wave (SAW) and Bulk Acoustic Wave (BAW) are the most commonly used technologies to manufacture filters for RF applications. The objective of the research described in this thesis is to investigate the feasibility of tunable filter solutions using piezoelectric SAW resonators. A tunable SAW technology which can maintain required performance parameters and can be commercially manufactured will constitute a technological breakthrough in wireless communications. Thin-Film Piezoelectric on Substrate (TPoS) resonators, based on Aluminum Nitride (AlN) piezoelectric material which are fabricated using commercially available Silicon on Insulator (SOI) PiezoMUMPs process, have been demonstrated. By combining the superior acoustic properties of AlN and single crystalline silicon substrate, this class of resonators achieves ultra-high quality factor (Q) values in excess of 3600. A 3-pole bandpass filter using direct electrical coupling between the resonators has been presented and we have studied the performance of the fabricated filter over a temperature range from -196ºC up to +120ºC and under high power. For the first time, we have demonstrated the integration of switching elements, based on Vanadium Dioxide (VO2) phase change material, with Incredible-High-Performance SAW (IHP-SAW) technology which allows us to design and implement switchable and reconfigurable SAW resonators and filters for wireless applications. Switchable multi-band filters using VO2 switches strategically imbedded within the resonators of the filter have been demonstrated. A switchable dual-band filter with four switching states and two channels was presented using hybrid integration approach where discrete VO2 switches were fabricated separately and then integrated with the SAW resonators and filters using wire bonds. The fabricated 5-pole dual-band filter demonstrated good insertion loss in both transmission states but had inadequate performance in terms of isolation between the channels due to the limitations of the hybrid integration approach. Moreover, hybrid integration does not allow us to use more than a few switching elements and cannot be used for the implementation of higher order filters. To address these issues, we have demonstrated the monolithic integration of VO2 switches using an in-house fabrication process that allows us to fabricate VO2 switches and SAW resonators and filters on a single chip. A dual-band switchable higher order 7-pole filter with six monolithically integrated VO2 switches, three for each channel, was demonstrated. The monolithic integration allows the single-chip implementation of the proposed switchable dual-band filter with improved performance along with significant size reduction and ease of manufacturing, paving the path for commercialization of this technology. Novel reconfigurable SAW resonators and filters with tunable center frequency were also presented for the first time. Tuning of the center frequency between two different states was achieved by changing the configuration of interdigitated electrodes within the SAW resonator and by using a set of tuning electrodes and VO2 switches. In the first implementation, the VO2 switches were integrated over the electrodes and inside the active area of the SAW resonator. Each resonator consists of hundreds of tuning electrodes and for a reliable switching each resonator requires a number of heater elements which results in increased DC power consumption and total size. A second reconfigurable resonator with a modified structure and using a modified in-house fabrication process to include a second electrode layer was proposed to reduce the number of required VO2 switching elements for an even more compact implementation and ten times reduction in the required DC power consumption. Design, implementation, and measurement results for a 3-pole tunable SAW filter based on the proposed reconfigurable resonators have been presented. The filter’s center frequency is tuned from 733 MHz to 713 MHz while the insertion loss was maintained below 2.5 dB. The fabricated SAW resonators and filters also showed acceptable linear and high-power performance characteristics. This is the first time a single-chip implementation of a reconfigurable SAW filter with center frequency tuning and acceptable RF performance using monolithically integrated VO2 switches is ever reported. The single-chip implementation of the proposed SAW resonators and filters enables the development of future low-cost RF multi-band transceivers with improved performance and functionality

Technologie BAW-SMR (synthèse des filtres pour une application spatiale et étude de l'accordabilité des filtres pour la téléphonie mobile avec la technologie CMOS 65nm)

Dans l optique de développer de nouveaux système RF les plus intégrés possibles, les technologies above-IC compatibles avec les technologies silicium ouvrent des perspectives prometteuses sur un plan économique pour l industrie du semi-conducteur. En effet, a contrario des résonateurs SAW et céramiques, les résonateurs à ondes acoustiques de volume (BAW) peuvent être fabriqués en utilisant des matériaux compatible CMOS VLSI pour des performances électriques comparables, voir supérieures dans certains cas en termes de fréquence et de puissance. Les travaux de cette thèse ont connus deux grandes partie ; la première a été focalisée sur le développement d une nouvelle topologie de filtre BAW accordable pour des applications de quatrième génération de téléphone mobile (4G). La seconde partie a été orientée vers une étude de faisabilité d un filtre BAW-SMR autour d une fréquence de travail à 7GHz pour une application spatiale.AbstractBORDEAUX1-Bib.electronique (335229901) / SudocSudocFranceF

Активные фильтры на тонкопленочных пьезоэлектрических резонаторах

Дисертація присвячена розробленню класу пристроїв частотної селекції сигналів на основі активних елементів і тонкоплівкових п’єзоелектричних резонаторів для діапазону частот 0,1..10 ГГц, що поєднують поліпшені електричні та експлуатаційні характеристики, а також можливість інтеграції за технологією ІС. Проведено дослідження ТПР методом скінченних елементів та розроблено широкосмугову модель резонатора, придатну для моделювання електричних характеристик конструкцій резонаторів мембранного типу та з бреггівським відбивачем. Розроблено модифіковану макромодель ОПС, у якій застосована секція нелінійного підсилення на основі поліномів Чебишева та включені нелінійні моделі теплового та флікер шумів. Проведено аналіз впливу реактивних навантажень з функцією перелаштування на характеристики ТПР. Наведено схеми активних імітаторів індуктивності та від’ємної ємності на основі ОПС. Показана можливість використання таких схем для реалізації ланок активних фільтрів з діапазоном перебудови до 200% та вище. Запропоновано метод перетворення імпедансу ТПР із використанням гіратора та показана практична можливість електронного перелаштування ефективної площі резонатора, що дозволяє зменшити габарити фільтрів. Розроблено алгоритм синтезу фільтрів, заснований на заміщенні прототипів пасивних LC фільтрів активними аналогами на ТПР, що забезпечують поліпшені характеристики за рахунок високої вихідної добротності і стабільності пасивної підсхеми. Приведені приклади застосування такого підходу для реалізації малогабаритних активних ФНЧ і ФВЧ на ТПР