DESIGN OF LOW POWER MOBILE TRANSMITTER

The objective of this project is to design a power amplifier for a new two way mobile radio product being launched by Motorola. Two-way mobile radio consists of a transmitter, receiver and a voltage-controlled oscillator. Mobile radios usually have transmitter whose power output ranges from 1 W to 50 W. Design of transmitter lineup for mobile radio involves the design of appropriate matching network for driver and power amplifier. The power and voltage control of these devices are equally important. Designing a mobile radio transmitter is regarded tricky due to difficulty in getting a robust transmitter that is stable with minimum oscillation. In this work, the design is attempted usmg Advanced Design Simulator (ADS). The design simulation provides accurate simulation on harmonic filter and antenna switch. 50 ohm matching networks have also been designed and simulated using ADS and it gives close approximation to the specifications. The radio has since been prototyped and tested. The evaluation and testing of the radio has been carried out and it satisfies the specifications that are set by the Telecommunication Industry Association (TIA). Some minor optimization has also been performed to improve the radio performance. Eventual product is a transmitter line up that function well today. 11

Product assurance technology for custom LSI/VLSI electronics

The technology for obtaining custom integrated circuits from CMOS-bulk silicon foundries using a universal set of layout rules is presented. The technical efforts were guided by the requirement to develop a 3 micron CMOS test chip for the Combined Release and Radiation Effects Satellite (CRRES). This chip contains both analog and digital circuits. The development employed all the elements required to obtain custom circuits from silicon foundries, including circuit design, foundry interfacing, circuit test, and circuit qualification

Metodologia Per la Caratterizzazione di amplificatori a basso rumore per UMTS

In questo lavoro si presenta una metodologia di progettazione elettronica a livello di sistema, affrontando il problema della caratterizzazione dello spazio di progetto dell' amplificatore a basso rumore costituente il primo stadio di un front end a conversione diretta per UMTS realizzato in tecnologia CMOS con lunghezza di canale .18u. La metodologia è sviluppata al fine di valutare in modo quantititativo le specifiche ottime di sistema per il front-end stesso e si basa sul concetto di Piattaforma Analogica, che prevede la costruzione di un modello di prestazioni per il blocco analogico basato su campionamento statistico di indici di prestazioni del blocco stesso, misurati tramite simulazione di dimensionamenti dei componenti attivi e passivi soddisfacenti un set di equazioni specifico della topologia circuitale. Gli indici di prestazioni vengono successivamente ulizzati per parametrizzare modelli comportamentali utilizzati nelle fasi di ottimizzazione a livello di sistema. Modelli comportamentali atti a rappresentare i sistemi RF sono stati pertanto studiati per ottimizzare la scelta delle metriche di prestazioni. L'ottimizzazione dei set di equazioni atti a selezionare le configurazione di interesse per il campionamento ha al tempo stesso richiesto l'approfondimento dei modelli di dispositivi attivi validi in tutte le regioni di funzionamento, e lo studio dettagliato della progettazione degli amplificatori a basso rumore basati su degenerazione induttiva. Inoltre, il problema della modellizzazione a livello di sistema degli effetti della comunicazione tra LNA e Mixer è stato affrontato proponendo e analizzando diverse soluzioni. Il lavoro ha permesso di condurre un'ottimizzazione del front-end UMTS, giungendo a specifiche ottime a livello di sistema per l'amplificatore stesso

DESIGN OF LOW POWER MOBILE TRANSMITTER

The objective of this project is to design a power amplifier for a new two way mobile radio product being launched by Motorola. Two-way mobile radio consists of a transmitter, receiver and a voltage-controlled oscillator. Mobile radios usually have transmitter whose power output ranges from 1 W to 50 W. Design of transmitter lineup for mobile radio involves the design of appropriate matching network for driver and power amplifier. The power and voltage control of these devices are equally important. Designing a mobile radio transmitter is regarded tricky due to difficulty in getting a robust transmitter that is stable with minimum oscillation. In this work, the design is attempted usmg Advanced Design Simulator (ADS). The design simulation provides accurate simulation on harmonic filter and antenna switch. 50 ohm matching networks have also been designed and simulated using ADS and it gives close approximation to the specifications. The radio has since been prototyped and tested. The evaluation and testing of the radio has been carried out and it satisfies the specifications that are set by the Telecommunication Industry Association (TIA). Some minor optimization has also been performed to improve the radio performance. Eventual product is a transmitter line up that function well today. 11

Optimising image quality for medical imaging

OPTIMAX 2016 was held at the University of Salford in Greater Manchester. It is the fourth summer school of OPTIMAX with other renditions having been organized at the University of Salford (2013), ESTeSL, Lisbon (2014) and Hanze UAS, Groningen (2015). For OPTIMAX 2016, 72 people participated from eleven countries, comprising PhD, MSc and BSc students as well as tutors from the seven European partner universities. Professional mix was drawn from engineering, medical physics/ physics and radiography. OPTIMAX 2016 was partly funded by the partner universities and partly by the participants. Two students from South Africa and two from Brazil were invited by Hanze UAS (Groningen) and ESTeSL (Lisbon). One student from the United Kingdom was funded by the Nuffield Foundation. The summer school included lectures and group projects in which experimental research was conducted in five teams. Each team project focus varied and included: optimization of full spine curvature radiography in paediatrics; ultrasound assessment of muscle thickness and muscle cross-sectional area: a reliability study; the Influence of Source-to-Image Distance on Effective Dose and Image Quality for Mobile Chest X-rays; Impact of the anode heel effect on image quality and effective dose for AP Pelvis: A pilot study; and the impact of pitch values on Image Quality and radiation dose in an abdominal adult phantom using CT. OPTIMAX 2016 culminated in a poster session and a conference, in which the research teams presented their posters and oral presentations. This book comprises of two sections, the first four chapters concern generic background information which has value to summer school organization and also theory on which the research projects were built. The second section contains the research papers in written format. The research papers have been accepted for the ECR conference, Vienna, 2017 as either oral presentations or posters

Optimax 2016 : peer observation of facilitation

In August 2016, a 3-week research Summer School was delivered at University of Salford. The Summer School, known as ‘OPTIMAX’ was in its fourth year of delivery. Previous iterations were held in the Netherlands (2015), Portugal (2014) and Salford (2013). The purpose of OPTIMAX is to facilitate collaborative international and interdisciplinary research between university academics and students. This offers an exceptional opportunity not only for students, but also for tutors who want to develop their facilitation skills. The project reported here used tutor observers (i.e. tutors who attend the summer school, in an observational capacity only, to develop their own skills as teachers) to observe, identify and reflect on a range of facilitation practices for managing the diverse OPTIMAX research groups. The project presents a description of the peer-observation method we used and highlights a number of findings related to facilitator strategies that appeared to influence group dynamics and learning. These observations are then used to make recommendations about how OPTIMAX tutors can be prepared for their facilitation experience

Multi-time analysis of CMOS circuits

Transient simulation of circuits with widely separated time constants and fast periodic excitations is not efficient because a long simulation period with small time steps is required. One approach to simulate the transient behaviour more efficiently is known as the Multi Partial Differential Equation (MPDE). In the MPDE the system ordinary differential equations that describe a circuit is transformed into a system of partial differential equations with two time variables, one for the fast periodic variations and another for the slow transient evolution. This method has been implemented in a general-purpose circuit simulator program named Carrot. This thesis presents progress towards the development that simulator. The main contributions of this thesis are the implementation and validation of MOSFET models in the simulator and the study of the performance of the MPDE approach (as currently implemented in Carrot) applied to complex CMOS circuits. An overview of concepts relevant for this work is presented, followed by a detailed description of the MOSFET model implementation. Next, the design of an integrated CMOS ring voltage-controlled oscillator is presented. This is followed by simulation case studies. The simulation results indicate that the MPDE approach can achieve orders of magnitude of improvement in simulation speed compared to regular transient analysis. This thesis concludes with recommendations for future research

Amplificadores paramétricos de RF

Mestrado em Engenharia Electrónica e TelecomunicaçõesRecentemente tem-se feito um esforço no sentido de aumentar a eficiência em aplicadores de RF, no entanto, o transístor é um dispositivo intrinsecamente ineficiente. Utilizando amplificadores paramétricos pode-se teoricamente chegar a 100% de eficiência mesmo operando em modo linear. A razão desta elevada eficiência é o dispositivo activo utilizado, já que os amplificadores paramétricos utilizam uma reactância controlada, que não consome potência. Esta mudança de elemento activo modifica completamente o princípio de funcionamento dos amplificadores. Neste trabalho este tipo de amplificação é estudado, relações e transformações conhecidas são examinadas primeiro para obter propriedades limite gerais. Depois é feita análise de pequeno sinal para se obterem outras características importantes. Finalmente, um novo modelo de grande sinal é derivado e apresentado. Este modelo é capaz de prever algumas características do amplificador, tal como o AM/AM. Utilizando o modelo de grande sinal apresentado projecta-se um amplificador, sendo este posteriormente simulado.In recent years a significant effort has been made towards efficiency increase in RF amplifiers. The transistor is, however, an intrinsically inefficient device. Parametric amplification can theoretically be 100% efficient even operating in linear mode. The reason behind this efficiency is the active device. These amplifiers forget the transistor to use a controlled reactance, which cannot consume power. This switch in active element changes the whole principle of operation of the amplifiers. In this work this type of amplification is studied. Known relations and transformations are first examined to obtain general limit properties of the used elements. Then small-signal analysis is performed to obtain other important characteristics. Finally, a novel large signal model is developed and presented. This model is capable of accurately predicting the non-linear responses of the amplifier, such as the AM/AM. Using the presented large-signal model, an amplifier is designed and simulated