A fully integrated CMOS 0 – 900 phase shifter in 0.18um TSMC technology is presented. With the increasing use of wireless systems in GHz range, there is high demand for integrated phase shifters in phased arrays and MIMO on chip systems. Integrated phase shifters have quite a high number of integrated inductors which consume a lot of area and introduce a huge amount of loss which make them impractical for on chip applications. Also tuning the phase shift is another concern which seems difficult with use of passive elements for integrated applications. This work is presents a new method for implementing phase shifters using only active CMOS elements which dramatically reduce the occupied area and make the tuning feasible. Also a fully integrated millimeter-wave VCO is implemented using the same technology. This VCO can be part of a 24 GHz frequency synthesizer for 24 GHz ISM band transceivers. The 24 GHz ISM band is the unlicensed band and available for commercial communication and automotive radar use, which is becoming attractive for high bandwidth data rate.

First, one of the purposes of this thesis is to estimate the complete crosstalk effects including the package and the pads on the surface acoustic wave (SAW) substrate. A new approach based on finite-difference time-domain (FDTD) with equivalent current source method is applied. Two kinds of patterns of one-port SAW resonators with the same package structure and inter-digital transducer (IDT) design are studied. Verification with the measurement results shows that our method is able to obtain good agreement and be used to observe the influence from the SAW pattern. Second, the equivalent current source method is extended to model the excitation of human-body¡¦s electrostatic discharge (ESD) situations. The efficiencies of sacrificial electrodes are also discussed. Finally, a novel sacrificial electrode with fractal to protect SAW devices from ESD break is proposed. Comparing with traditional electrode, the simulation results show that fractal can improve the protective efficiency greatly. Finally, a novel analysis model that can be used to analyze and optimize the impedance of an RFID transponder integrated circuit (IC) which uses backscatter encoding based on simultaneously maintaining the BER of the reader and maximizing the received power of the transponder IC is proposed. The analysis method utilizes mapping from signal constellation of the backscattered signal to the Smith chart to relate the two parameters. Given the system specification and characteristics of the reader and transponder antennas, the optimum impedances of transponder IC for binary communication system can be easily designed by using this model.

The objective of this research is to analyze and improve linearity of envelope elimination and restoration (EER) radio frequency (RF) power amplifiers. Envelope elimination and restoration was compared to other efficiency enhancement techniques and determined to likely be the most suitable solution for implementation of multimode, multiband portable RF transmitters. Distortion, stemming from dynamic power-supply modulation of RF transistors in EER RF power amplifiers was identified as one of the key challenges to the development of commercially viable EER transmitters. This dissertation presents a study of phase distortion in RF power amplifiers (PAs) with emphasis on identification of the origins of phase distortion in EER RF power amplifiers. Circuit-level techniques for distortion mitigation are also presented. Memory effects in conventional power amplifiers are investigated through the accurate measurement and analysis of phase asymmetry of out-of-band distortion components. Novel physically-based power amplifier model is developed for attributing measured memory effects to their physical origin. The amount of linearity correction, obtained through pre-distortion for a particular RF power amplifier, is then correlated to the behavior of the memory effects in the corresponding PA. Heterojunction field-effect transistor and heterojunction bipolar transistor amplifiers are used for investigation of voltage-dependent phase distortion in handset EER RF PAs. The distortion is found to stem from vector addition of signals, generated in nonlinear circuit elements of the PA. Specifically, nonlinear base-collector capacitance and downconversion of distortion components from second harmonic frequency are found to be the dominant sources of phase distortion. Shorting of second harmonic is proposed as a way to reduce the distortion contribution of the downconverted signal. Phase distortion is reduced by 50%, however a slight degradation in the amplitude distortion is observed. Push-pull architecture is proposed for EER RF power amplifiers to cancel distortion components, generated in the nonlinear base-collector capacitance. Push-pull implementation enables a 67% reduction in phase distortion, accompanied by a 1-2 dB reduction in amplitude distortion in EER RF power amplifiers. This work, combined with other studies in the field, will help advance the development of multimode, multiband portable RF transmitters, based on the envelope elimination and restoration architecture.

The reliability of RFID systems depends on a number of factors including: RF interference, deployment environment, configuration of the readers, and placement of readers and tags. While RFID technology is improving rapidly, a reliable deployment of this technology is still a significant challenge impeding wide-spread adoption. This research investigates system software solutions for achieving a highly reliable deployment that mitigates inherent unreliability in RFID technology. We have considered two different problem domains for large scale RFID deployment. One is item tracking and the other is guidance-monitoring. Item tracking considers applications that have statically placed RFID readers to observe the RFID tagged objects in motion. An airport scenario to observe the tagged baggage or warehouse scenarios to track the tagged goods are examples of item tracking applications. A self guided tour, search and rescue scenario or a visually impaired person looking for direction and guidance in a tagged environment are examples of item location applications. It is observed that there is a notion of path that follows the direction and flow of the mobile items in the item tracking applications and a path gets created along the direction and flow of the mobile object in item location applications. A system level knowledge of the data flow can benefit the system in different aspects such as improved reliability, resource management and real time response. We have designed and implemented an RFID middleware for item tracking: RF²ID (Reliable Framework for Radio Frequency Identification) to organize and support queries over data streams in an efficient manner. We have developed (1) a virtual reader abstraction to improve the potentially error-prone nature of reader generated data (2) a novel path abstraction to capture the logical flow of information among virtual readers. Prototype implementation using both RFID readers and simulated readers using an empirical model of RFID readers show that RF²ID is able to provide high reliability, support path-based object detection and use efficient resource management techniques. We propose a middleware solution that takes into account the data flow information for item location application that requires real time response. The guidance-monitoring scenario considers mobile RFID readers that traverse in a tagged environment. We consider the scenario of an Assisted Living Center for elderly residents as a motivating guidance-monitoring application. The solution for guidance-monitoring system is called GuardianAngel. The application scenario considers a tagged indoor environment with residents having their own RFID readers to provide them with adequate information about the surroundings. The guidance and monitoring requirement can be conflicting. The guidance information requires very fine grain information about the environment to make proper decisions. On the other hand, the monitoring system must not have a fine grain knowledge which can introduce concerns such as privacy concerns. We consider this aspect during the design and implementation. The system is a two layered infrastructure that has the upper layer which is the monitoring layer. This layer is in charge of monitoring of the actors in the environment. The monitoring layer is physically a set of distributed virtual stations that have the knowledge about the environment. The environment itself is equipped with RFID tags. The residents of the environment have the mobile object that has a sensing element and a computing element (e.g., handhold device with a portable RFID reader) - the guidance server runs on this mobile object. The guidance server is in charge of making local decisions to the users. It is resource limited and asks for new information from the virtual stations as needed. The guidance server also provides the monitoring server with the information regarding the status of the mobile object. But the status information is not fine grain information - the guidance server wraps up the information over a period of time and over a larger region to hide the detailed information of the users.The system uses the logical path based abstraction to guide the users. We have implemented the real testbed using grid structured RFID devices along with scalability study using emulated RFID readers. The basic contribution of our work is based on providing novel middleware solution that is able to serve the application taking into account the inherent unreliability of RFID technology. Our path abstraction that uses the physical flow of data as an ally to generate a logical system level flow enhances the performance in many ways.

Until recent developments, labor productivity had been analyzed manually requiring time-consuming work and the possibility of human error. Past research has shown the multitude of benefits obtained from implementing radio frequency identification technology within various construction sites including asset tracking, inventory management, and on-site security upgrades. Additional construction improvements can be identified in terms of productivity analysis of work crews, material transport, and the overall approach to a project to determine whether the construction process is operating at maximum efficiency or can be adjusted to improve its effectiveness. This paper presents the results of implementing radio-frequency identification technology and provides a study of labor productivity analysis for a window replacement project on a high-rise construction site. This extensive study tracks the efficiency of a buck hoist worker and material lift system for transportation and illustrates the applicability of the technology despite the presence of numerous signal impeding obstacles located throughout the site. These issues are resolved with an effective automated location and time tracking system that work in both an indoor and outdoor environment simultaneously with a data recording software and database. The in-house development of the database allows for timely information retrieval of various items of interest in this study and requires less The experimental results show that RFID technology has the capacity to work and produce useful data for labor productivity purposes in an ever-changing construction environment. The research further recognizes relevant information regarding system optimization and worker feedback for future use.

Switching frequency modulation techniques, an inductor current sensing circuit for fast switching converter, and a dual converter are proposed, and the simulation results and experimental results are drawn. The experimental results for monotonic and pseudo-random modulation techniques show that the switching noise peak was effectively reduced as much as -19 dBc. The inductor current sensing circuit accurately tracks the output current of the switching converter that switches up to 30MHz. This current sensing circuit is used to drive the slow converter in the dual converter. The dual converter consists of a fast converter and a slow converter. The fast converter provides only the high frequency conponents in the output current, and the slow converter provides the majority portion of the output current with a higher efficiency. Therefore, the dual converter can have a fast transient response without sacrificing its efficiency. All chips are fabricated in a standard CMOS 0.18um process.

The objective of this research is to develop, characterize, and demonstrate novel parametric architectures capable of wideband operation while maintaining high gain and stability. To begin the study, phase-incoherent upconverting parametric amplifiers will be explored by first developing a set of analytical models describing their achievable gain and efficiency. These models will provide a set of design tools to optimize and evaluate prototype circuit boards. The prototype boards will then be used to demonstrate their achievable gain, bandwidth, efficiency, and stability. Further investigation of the analytical models and data collected from the prototype boards will conclude bandwidth and gain limitations and end the investigation into phase-incoherent upconverting parametric amplifiers in lieu of negative-resistance parametric amplifiers. Traditionally, there were two versions of negative-resistance parametric amplifiers available: degenerate and non-degenerate. Both modes of operation are considered single-frequency amplifiers because both the input and output frequencies occur at the source frequency. Degenerate parametric amplifiers offer more power gain than their non-degenerate counterpart and do not require additional circuitry for idler currents. As a result, a phase-coherent degenerate parametric amplifier printed circuit board prototype will be built to investigate achievable gain, bandwidth, and stability. Analytical models will be developed to describe the gain and efficiency of phase-coherent degenerate parametric amplifiers. The presence of a negative resistance suggests the possibility of instability under certain operating conditions, therefore, an in-depth stability study of phase-coherent degenerate parametric amplifiers will be performed. The observation of upconversion gain in phase-coherent degenerate parametric amplifiers will spark investigation into a previously unknown parametric architecture: phase-coherent upconverting parametric amplifiers. Using the phase-coherent degenerate parametric amplifier prototype board, stable phase-coherent upconversion with gain will be demonstrated from the source input frequency to its third harmonic. An analytical model describing the large-signal transducer gain of phase-coherent upconverting parametric amplifiers from the first to the third harmonic of the source input will be derived and validated using the prototype board and simulations.

Gamybos pramonės sektorius apima viena iš didžiausių ir pelningiausią rinkos sektorių pasaulyje. Norėdamos išlikti ir sėkmingai dirbti besikeičiančios konkurencinės rinkos sąlygomis, įmonės neišvengiamai susiduria su konkurencinio pranašumo didinimo poreikiu. Tuo tikslu yra kuriamos veiklos vystymo strategijos, taikoma naujų technologijų diegimas, verslo valdymo procesų tobulinimas, produktų kokybės didinimas, valdymas, kokybės reikalavimų ir standartų taikymas. Vienas iš gamybos kokybės proceso optimizavimo sprendimas gali būti RFID technologijos pritaikymas gamybos veiklose. RFID yra viena naujausių ir besivystančių technologijų, kuri pasaulyje yra pritaikoma ir naudojama įvairiose srityse. Įgyvendintas projektas ir jo pasakoje sukurta RFID sistemos modulis, bei priemonės gali būti naudojamos, ne tik su užsakovo UAB „RTech“ plėtojama „QMS“ (Quality Management Systems) programinę įrangą, bet ir kaip sąsaja tarp RFID įrangos ir vartotojo veiklos taikomosios programos. Panaudojus RFID technologas ir sąsajas su RFID technologijomis galima: • dalinai automatizuoti gamybos kokybės valdymo procesą, • padidinti efektyvumą gaminio atsekamume, • sumažinti broko kontrolę tiekiant gaminius užsakovui. Šio darbo vienas iš tikslų yra įvertinti sukurta sistemą ir ką būtu galima patobulinti, kad būtų galima padaryti lankstesne pritaikant darbui su kitomis programinės įrangos sistemomis. Darbo metu yra tiriami ir analizuojami ISO standartų RFID sistemų modeliai, bei jų pritaikymo galimybės... [toliau žr. visą tekstą] / Manufactory industry is the most profitable sector of world’s market. Companies confronts with competitive market advantages to keep working successfully in continually changing market conditions. Therefore activities development strategies are created, new technologies are used in installation process, perfection of business control process, increasing quality of products, use of standards and quality requirements. The solution of these problems can be use of RFID (Radio Frequency Identification) technologies in manufacture management process. RFID is an automatic identification technology that relies on cheap tags (transponders) that can be attached to objects and storage information on it. The results of this project are RFID systems components witch can be used with other users applications such as „QMS“ (Quality Management Systems) of “RTech” company or other users applications. The successful integration of RFID technologies in manufacture quality management process can give effect in: • Automate and computerize manufacture quality management process; • Increase efficiency of product traceability system process; • Reduce rejects on product supply for consumer’s process. One of the master’s work goals is to evaluate the system, which was created in this work. The system can be improved by ISO standard models and made more flexible to use it for other works.

Plasma enhanced chemical vapor deposition systems are massively deployed to grow numerous thin film coatings including hydrogenated amorphous silicon. A new deposition chamber was designed, procured, and constructed to investigate the plasma properties of a 100% silane (SiH4) glow discharge with varying chamber pressure and inter-electrode spacing. A Hiden EQP1000 ion mass spectrometer sampled the plasma from the substrates point of view. Ion energy distributions were obtained using four different excitation sources +DC, –DC, radio frequency (at 13.56 MHz), and the DC Saddle Field (DCSF) in the tetrode configuration. The shape of the ion energy distributions was constant for the capacitively coupled +DC, –DC, and rf (at higher pressures of 75 and 160 mTorr) glow discharges. The shape of the ion energy distributions for the DCSF plasma exhibited a double peak or saddle structure analogous to radio frequency plasmas. The width between the peaks (peak separation) was controlled by the pressure and the semi-transparent cathode to semi-transparent anode distance. Ion energy distributions from the DCSF plasma concurred with rf and +DC ion energy distributions at specific pressures and inter-electrode distances. This result demonstrates the versatility of the DCSF glow discharge system. Moreover, control of the peak separation is modeled to be iii equivalent to controlling the critical ratio (ion transit time in the sheath to the electron oscillating period), and/or the inferred electron oscillating sheath potential. The DCSF possesses a fusion of rf and +DC methods. The long high energy tail or constant background are indicative of a +DC high voltage sheath in which there is an increasing fraction of collisionless ions as the anode-cathode distance increases. These collisionless ions are provided by the oscillating electrons (or rf nature) of the DCSF method. Higher order silane (silicon containing) ions increase in relative intensity with increasing inter-electrode spacing for the +DC, –DC, and rf plasmas. These higher order silane ions are also detected in the DCSF plasma, and can be reduced at either lower pressure or lower cathode to anode or cathode to substrate distances.

Plasma enhanced chemical vapor deposition systems are massively deployed to grow numerous thin film coatings including hydrogenated amorphous silicon. A new deposition chamber was designed, procured, and constructed to investigate the plasma properties of a 100% silane (SiH4) glow discharge with varying chamber pressure and inter-electrode spacing. A Hiden EQP1000 ion mass spectrometer sampled the plasma from the substrates point of view. Ion energy distributions were obtained using four different excitation sources +DC, –DC, radio frequency (at 13.56 MHz), and the DC Saddle Field (DCSF) in the tetrode configuration. The shape of the ion energy distributions was constant for the capacitively coupled +DC, –DC, and rf (at higher pressures of 75 and 160 mTorr) glow discharges. The shape of the ion energy distributions for the DCSF plasma exhibited a double peak or saddle structure analogous to radio frequency plasmas. The width between the peaks (peak separation) was controlled by the pressure and the semi-transparent cathode to semi-transparent anode distance. Ion energy distributions from the DCSF plasma concurred with rf and +DC ion energy distributions at specific pressures and inter-electrode distances. This result demonstrates the versatility of the DCSF glow discharge system. Moreover, control of the peak separation is modeled to be iii equivalent to controlling the critical ratio (ion transit time in the sheath to the electron oscillating period), and/or the inferred electron oscillating sheath potential. The DCSF possesses a fusion of rf and +DC methods. The long high energy tail or constant background are indicative of a +DC high voltage sheath in which there is an increasing fraction of collisionless ions as the anode-cathode distance increases. These collisionless ions are provided by the oscillating electrons (or rf nature) of the DCSF method. Higher order silane (silicon containing) ions increase in relative intensity with increasing inter-electrode spacing for the +DC, –DC, and rf plasmas. These higher order silane ions are also detected in the DCSF plasma, and can be reduced at either lower pressure or lower cathode to anode or cathode to substrate distances.