Millimetre-wave optically injection-locked oscillators for radio-over-fibre systems

Theoretical analysis and experimental results for millimetre-wave optically injection-locked oscillators are presented in this thesis. Such oscillators can be employed to replace conventional photodiode plus amplifier receivers for local oscillator signal reception in millimetre-wave radio-over-fibre systems. The theories for electrical injection-locked oscillators are reviewed in detail. Three differences between Adler’s and Kurokawa’s equations for locking bandwidth are highlighted for the first time. These differences are the absence of l/cos# factor in Adler’s equation, larger bandwidth predicted by Kurokawa’s equation, and a difference in definition of Q factors. Locking bandwidth equations for optically injection-locked oscillators are developed based on the theories of electrical injection-locked oscillators and are then used to design optically injection-locked oscillators. A novel millimetre-wave indirect optically injection-locked oscillator is presented. An edge-coupled photodiode is used to detect the optical signal. Negative resistance and computer simulation techniques were used for predicting the free running oscillation frequency. The maximum output power of the oscillator is 5.3 dBm, and the maximum locking bandwidth is measured to be 2.6 MHz with an output power o f-12 dBm. Results from a comparison with conventional optical receivers show that the gain of the optically injection-locked oscillator is more than 10 dB higher than that of a photodiode plus amplifier receiver, that the oscillator output power remains constant with input signal power variations whereas the output power of the photodiode plus amplifier receiver changes (linearly) with the input signal power, and that, at high-offset frequencies, the phase noise of the optically injection-locked oscillator is much lower than that of the photodiode plus amplifier receiver. These advantages make the optically injection-locked oscillator an ideal replacement for the photodiode plus amplifier receiver in radio-over-fibre systems. An improved wide-band design for millimetre-wave optically injection-locked oscillators is presented for future work

Design and Control of Power Converters 2019

In this book, 20 papers focused on different fields of power electronics are gathered. Approximately half of the papers are focused on different control issues and techniques, ranging from the computer-aided design of digital compensators to more specific approaches such as fuzzy or sliding control techniques. The rest of the papers are focused on the design of novel topologies. The fields in which these controls and topologies are applied are varied: MMCs, photovoltaic systems, supercapacitors and traction systems, LEDs, wireless power transfer, etc

A review on power electronics technologies for electric mobility

Concerns about greenhouse gas emissions are a key topic addressed by modern societies worldwide. As a contribution to mitigate such effects caused by the transportation sector, the full adoption of electric mobility is increasingly being seen as the main alternative to conventional internal combustion engine (ICE) vehicles, which is supported by positive industry indicators, despite some identified hurdles. For such objective, power electronics technologies play an essential role and can be contextualized in different purposes to support the full adoption of electric mobility, including on-board and off-board battery charging systems, inductive wireless charging systems, unified traction and charging systems, new topologies with innovative operation modes for supporting the electrical power grid, and innovative solutions for electrified railways. Embracing all of these aspects, this paper presents a review on power electronics technologies for electric mobility where some of the main technologies and power electronics topologies are presented and explained. In order to address a broad scope of technologies, this paper covers road vehicles, lightweight vehicles and railway vehicles, among other electric vehicles.This work has been supported by FCT – Fundação para a Ciência e Tecnologia with-in the Project Scope: UID/CEC/00319/2020. This work has been supported by the FCT Project DAIPESEV PTDC/EEI-EEE/30382/2017, and by the FCT Project new ERA4GRIDs PTDC/EEI-EEE/30283/2017. Tiago Sousa is supported by the doctoral scholarship SFRH/BD/134353/2017 granted by FCT

7th EEEIC International Workshop on Environment and Electrical Engineering : Wroclaw - Cottbus, 5 - 11. May 2008

The proposed solution meets the latest trends in world power engineering and has the lowest ecological costs amongst the accessible power engineering solutions. It is also in accordance with the Polish power engineering law, which takes into account the recommendations of the European Economic Commission, the Second Sulphur Protocol and the Framework Convention of the United Nations (concerning the changes of climate)