A Novel Micro Piezoelectric Energy Harvesting System

(Doktora) -- İstanbul Teknik Üniversitesi, Fen Bilimleri Enstitüsü, 2007(PhD) -- İstanbul Technical University, Institute of Science and Technology, 2007Bu tezde yeni bir titreşim temelli mikro enerji harmanlayıcı sistemi önerilmiştir. Titreşimler ve ani hareketler, mekanik yapının sadece eğilmesine değil aynı zamanda gerilmesine yol açar, bu sayede sistem doğrusal olmayan bölgede çalışır. İnce piezoelektrik film tabakası mekanik stresi elektrik enerjisine çevirir. Mikrowatt mertebesinde güç seviyeleri mm3’lük aletlerle elde edilebilir, bu da güneş panellerinde elde edilen güç yoğunlukları kadar yüksektir. Algılayıcı kabiliyeti sayesinde bilgi depolayabilen, kum tanesi büyüklüğünde olan ve üretiminde kullanılan temel malzeme silikon olan bu aletler “zeki kum” olarak isimlendirilmiştir. Mekanik yapının modellenmesi ve tasarımı geliştirilmiş ve üretim sonuçları da ayrıca verilmiştir. Sistemin bilgi gönderebilmesi ve alabilmesi amacıyla iyi bilinen RFID teknolojisi tabanlı bir kablosuz haberleşme yöntemi önerilmiştir. Bu bağlamda, paket taşımacılığında sürekli ivme denetleme, sınır güvenliği için kendinden beslemeli algılayıcılar, çabuk bozulan yiyeceklerin taşımacılığında sıcaklık denetleme ve pilsiz kalp atışı algılayıcı gibi birçok uygulama önerilmiştir.In this thesis, a novel, vibration based micro energy harvester system is proposed. Vibrations or sudden movements cause the mechanical structure does not only bend but also stretch, thus working in non-linear regime. The piezoelectric thin film layer converts the mechanical stress into the electrical energy. Microwatts of power can be achieved with a mm3 device which yields a high power density levels on the order of the solar panels. This device is named “smart sand”, because it has also sensor capabilities that can store information, its size is almost a sand grain and the main material used for the fabrication is silicon. The modeling and design of the mechanical structure has been developed and fabrication results have also been given in the thesis. In order for the system to send and receive the information, a wireless communication scheme is proposed which is based on the well-known RFID technology. In this concept, several applications are proposed such as continuous acceleration monitoring in package delivery, self-powered sensors for homeland security, temperature monitoring of the perishable food item delivery and a batteryless heart rate sensor.DoktoraPh

Low-power CMOS rectifier and Chien search design for RFID tags

Automotive sensors implemented in radio frequency identification (RFID) tags can correct data errors by using BCH (Bose-Chaudhuri-Hocquenghem) decoder, for which Chien search is a computation-intensive key step. Existing low power approaches have drastically degrading performance for multiple-bit-correcting codes. This thesis presents a novel approach of using register-transfer-level (RTL) power management in the search process, leading to significant power savings for BCH codes with higher correction capability. An example for the (255, 187, 9) BCH code has been implemented in 0.18μm CMOS technology. We also consider ways of conserving power for the sole power harvester on a passive tag – the rectifier. With ST CMOS 90nm technology, a three-stage differential-drive CMOS rectifier is designed by using a new transistor scaling method and a piece-wise linear matching technique. For the standard 915MHz band, simulation indicates high power conversion efficiency (PCE) of 74% and a significantly increased output power of 30.3μW at 10 meters

Compact design of UHF RFID and NFC antennas for mobile phones

A small size and low-profile antenna has been developed in order to provide any mobile phone with ultra-high frequency (UHF) radiofrequency identification (RFID) reader functionality. For that purpose, a patch antenna topology has been chosen on account of the mobile phone battery, which exhibits an electromagnetic behaviour similar to a metal plane. The low- profile patch antenna has been designed to operate at the European UHF RFID band. To communicate the mobile phone with the RFID reader module, near-field communication (NFC) technology has been considered. Thus, an NFC antenna, based on square coils, operating at 13.56 MHz has been also designed. Such antenna has been etched on the opposite side of the patch antenna. Overall dimensions of the prototype are 60 mm × 100 mm, i.e. small enough to fit the dimensions of a mobile phone. As proof of concepts to evaluate the performance of the designed antennas, an UHF RFID reader module and an NFC reader module are tested. The measured read range reaches up to 1 m for some commercial tags

Broadband UHF-RFID passive tag based on split-ring resonator (SRR) and T-match network

A novel broadband design of a planar passive UHF-RFID tag based on a split-ring resonator (SRR) antenna and the T-match network is presented in this work. The radiation properties of the SRR working at its second resonance are exploited to design a radio frequency identification (RFID) tag for the first time. The potential usefulness of the T-match based design methodology to achieve perfect matching between the SRR antenna and any typical RFID chip is demonstrated. A 0.23 λ₀ × 0.23 λ₀ tag has been fabricated. The measured read range is higher than 13 m within the whole UHF-RFID band with a peak value of 16 m at 915 MHz

Design of a Low-Cost Passive UHF RFID tag in 0.18um CMOS technology

The work addresses the design of a passive UHF Radio-Frequency Identification (RFID) tag. In order to realize a product able to be competitive in the RFID expanding market, a cost reduction policy has been applied in the design: a general purpose digital technology has been employed, resorting to specific techniques in order to overcome the limitations due to the lack of process options. Such solutions are accurately described, and every block composing the transponder analog frontend is analyzed, highlighting advantages and disadvantages of the proposed architectures with respect to the ones present in literature. The circuits theory is validated through simulations and experimental data.Il lavoro di tesi è imperniato sul progetto di un tag passivo per l'Identificazione a Radio-Frequenza (RFID) operante nelle bande UHF. Per il progetto è stata applicata una politica di riduzione dei costi, così da proporre un prodotto in grado di essere competitivo nel fiorente mercato dell'RFID: è stata scelta una tecnologia digitale general-purpose, e specifiche tecniche di progettazione sono state utilizzate per superare le limitazioni dovute alla scarsità di opzioni di processo. Le soluzioni adottate sono descritte accuratamente, ed è riportata l'analisi di ogni singolo blocco componente il frontend analogico, evidenziando vantaggi e svantaggi delle architetture proposte rispetto a quelle presenti in letteratura. La validità della teoria alla base dei circuiti è stata verificata tramite simulazioni e dati sperimentali

Advanced Radio Frequency Identification Design and Applications

Radio Frequency Identification (RFID) is a modern wireless data transmission and reception technique for applications including automatic identification, asset tracking and security surveillance. This book focuses on the advances in RFID tag antenna and ASIC design, novel chipless RFID tag design, security protocol enhancements along with some novel applications of RFID

Upper bounds on the bandwidth of electrically small single-resonant UHF-RFID tags

In this communication, the upper limits on the bandwidth of single-resonant UHF-radio frequency identification (RFID) tags as a function of the tag size are investigated, with and without forcing perfect matching between the antenna and the application-specific integrated circuit. By means of a circuit network analysis, it is found that bandwidth upper bounds of small tags are significantly higher in comparison with considering conjugate matching. Particularly, it is shown that the half-power bandwidth is √2 times (approximately 41%) higher, requiring a proper relaxation of the matching level at resonance. It is also shown that bandwidth of small real tags with perfect matching, which is typically far from its upper bound, can also be enhanced approximately the same factor at the expense of a small reduction (13.4%) in the peak read range. A practical example is provided, where two small split-ring resonator-based tags of the same size (k 0 a = 0.31) are designed. It demonstrates that such improvement on the tag bandwidth can be approximately obtained by simply changing the chip position, without the need of an external matching network. The improved tag was fabricated and measured, as a proof of concept. The results obtained from the proposed analysis allow RFID designers to determine how well a tag performs, compared to theoretical bandwidth limits

Sistemas eficientes de transmissão de energia sem-fios e identificação por radiofrequência

Doutoramento em Engenharia EletrotécnicaIn the IoT context, where billions of connected objects are expected to be ubiquitously deployed worldwide, the frequent battery maintenance of ubiquitous wireless nodes is undesirable or even impossible. In these scenarios, passive-backscatter radios will certainly play a crucial role due to their low cost, low complexity and battery-free operation. However, as passive-backscatter devices are chiefly limited by the WPT link, its efficiency optimization has been a major research concern over the years, gaining even more emphasis in the IoT context. Wireless power transfer has traditionally been carried out using CW signals, and the efficiency improvement has commonly been achieved through circuit design optimization. This thesis explores a fundamentally different approach, in which the optimization is focused on the powering waveforms, rather than the circuits. It is demonstrated through theoretical analysis, simulations and measurements that, given their greater ability to overcome the built-in voltage of rectifying devices, high PAPR multi-sine (MS) signals are capable of more efficiently exciting energy harvesting circuits when compared to CWs. By using optimal MS signals to excite rectifying devices, remarkable RF-DC conversion efficiency gains of up to 15 dB with respect to CW signals were obtained. In order to show the effectiveness of this approach to improve the communication range of passive-backscatter systems, a MS front-end was integrated in a commercial RFID reader and a significant range extension of 25% was observed. Furthermore, a software-defined radio RFID reader, compliant with ISO18000-6C standard and with MS capability, was constructed from scratch. By interrogating passive RFID transponders with MS waveforms, a transponder sensitivity improvement higher than 3 dB was obtained for optimal MS signals. Since the amplification and transmission of high PAPR signals is critical, this work also proposes efficient MS transmitting architectures based on space power combining techniques. This thesis also addresses other not less important issues, namely self-jamming in passive RFID readers, which is the second limiting factor of passive-backscatter systems. A suitable self-jamming suppression scheme was first used for CW signals and then extended to MS signals, yielding a CW isolation up to 50 dB and a MS isolation up 60 dB. Finally, a battery-less remote control system was developed and integrated in a commercial TV device with the purpose of demonstrating a practical application of wireless power transfer and passive-backscatter concepts. This allowed battery-free control of four basic functionalities of the TV (CH+,CH-,VOL+,VOL-).No contexto da internet das coisas (IoT), onde são esperados bilhões de objetos conectados espalhados pelo planeta de forma ubíqua, torna-se impraticável uma frequente manutenção e troca de baterias dos dispositivos sem fios ubíquos. Nestes cenários, os sistemas radio backscatter passivos terão um papel preponderante dado o seu baixo custo, baixa complexidade e não necessidade de baterias nos nós móveis. Uma vez que a transmissão de energia sem fios é o principal aspeto limitativo nestes sistemas, a sua otimização tem sido um tema central de investigação, ganhando ainda mais ênfase no contexto IoT. Tradicionalmente, a transferência de energia sem-fios é feita através de sinais CW e a maximização da eficiência é conseguida através da otimização dos circuitos recetores. Neste trabalho explora-se uma abordagem fundamentalmente diferente, em que a otimização foca-se nas formas de onda em vez dos circuitos. Demonstra-se, teoricamente e através de simulações e medidas que, devido à sua maior capacidade em superar a barreira de potencial intrínseca dos dispositivos retificadores, os sinais multi-seno (MS) de elevado PAPR são capazes de excitar os circuitos de colheita de energia de forma mais eficiente quando comparados com o sinal CW tradicional. Usando sinais MS ótimos em circuitos retificadores, foram verificadas experimentalmente melhorias de eficiência de conversão RF-DC notáveis de até 15 dB relativamente ao sinal CW. A fim de mostrar a eficácia desta abordagem na melhoria da distância de comunicação de sistemas backscatter passivos, integrou-se um front-end MS num leitor RFID comercial e observou-se um aumento significativo de 25% na distância de leitura. Além disso, desenvolveu-se de raiz um leitor RFID baseado em software rádio, compatível com o protocolo ISO18000-6C e capaz de gerar sinais MS, com os quais interrogou-se transponders passivos, obtendo-se ganhos de sensibilidade dos transponders maiores que 3 dB. Uma vez que a amplificação de sinais de elevado PAPR é uma operação crítica, propôs-se também novas arquiteturas eficientes de transmissão baseadas na combinação de sinais em espaço livre. Esta tese aborda também outros aspetos não menos importantes, como o self-jamming em leitores RFID passivos, tido como o segundo fator limitativo neste tipo de sistemas. Estudou-se técnicas de cancelamento de self-jamming CW e estendeu-se o conceito a sinais MS, tendo-se obtido isolamentos entre o transmissor e o recetor de até 50 dB no primeiro caso e de até 60 dB no segundo. Finalmente, com o objetivo de demonstrar uma aplicação prática dos conceitos de transmissão de energia sem fios e comunicação backscatter, desenvolveu-se um sistema de controlo remoto sem pilhas, cujo protótipo foi integrado num televisor comercial a fim de controlar quatro funcionalidades básicas (CH+,CH-,VOL+,VOL-)

تصميم هوائي مع دائرة تقويم لتطبيقات حصاد طاقة الميكروويف

ABSTRACT Energy harvesting technology has received a lot of attention as the demand of long life span of energy source increase. Towards that, Rectenna (Rectifier Antenna) or Energy Harvesting system is designed in the current work and it consists of antenna, matching circuit and a rectifier circuit. Microstrip patch antenna where designed to harvest GSM signals. Single-patch antenna and array antennas are designed at 900 MHz for this purpose. The designed antenna has good return loss performance and the array antennas are designed to achieve higher gain and hence more captured energy. The design and optimizing of the performance of the proposed antenna are performed by using Computer Simulation Technology software CST studio design. The rectifier circuit is a 7 stage voltage doubler circuit using Schottky diodes and it is designed to convert the RF energy into a DC output. A matching circuit has been designed from a single stub to match the complex input impedance of the rectifier circuit to the standard 50 Ω. The design of the rectifier circuits is performed by using NI Multisim 14 software and the output voltage of rectifier was 2.283V. A single stage rectifier circuit along with matching circuit are fabricated on an FR-4 substrate.تكنولوجيا حصاد الطاقة لاقت الكثير من الاهتمام، من حيث زيادة الطلب لإطالة العمر الافتراضي لمصادر الطاقة. لذلك، في هذا المشروع تم تصميم نظام لحصاد الطاقة، وهذا النظام يتكون من ثلاثة دوائر، في الدائرة الأولى تم تصميم هوائي يعمل على تردد شبكات الاتصالات الخلوية الجوال التي تعمل بنظام ال GSM بتردد 900 ميجا هيرتز حيث تنبعث من هذا الهوائي طاقة كهرومغناطيسية مترددة صغيرة جدا يمكن استغلالها في حصاد الطاقة ولزيادة هذه الطاقة المنبعثة تم تصميم اثنين من هذه الهوائيات بنظام سلسلة Array للحصول على طاقة منبعثة عالية نوعا ما وتم التصميم باستخدام برنامج المحاكاة الحاسوبي CST microwave studio. الدائرة الثانية هي عبارة عن دائرة تعديل مع مضاعفة الجهد للطاقة المستقبلة من الهوائي في الدائرة الأولى وتتكون هذه الدائرة من سبع مستويات في كل مستوى تم استخدام اثنين من ثنائيات شوتكي Schottky diode HSMS-2850 حيث تم تحويل طاقة ترددات الراديو المستقبلة الى تيار كهربائي مستمر ومضاعفته سبع مرات بعدد مستويات الدائرة والحصول على جهد يقدر ب 2.283Volts باستخدام برنامج المحاكاة الحاسوبي NI Multisim 14. الدائرة الثالثة هي عبارة عن دائرة تتوسط الدائرتين السابقتين تسمى دائرة التوافق تعمل على التوفيق ما بين الجهد المستقبل من الهوائي الذي يعمل بنظام ال 50 اوم ودائرة تعديل ومضاعفة الجهد التي تعمل بنظام الجهد الكهربائي وحصد أكبر طاقة ممكنة من خلال تمرير كل الطاقة المستقبلة من الهوائي لدائرة التعديل ومضاعفة الجهد. في هذا المشروع، عمليا تم تصميم دائرة التوافق مع مستوى واحد من دائرة مضاعفة الجهد لعدم توفر مكونات التصميم في السوق لتصميم الدائرة كاملة ولم نتمكن من اختبارها لعدم توفر أجهزة القياس المراد استخدامها بفعل الحصار والتضييق