Design and realization of high power low loss combiners

Suna, Gonca
In recent high power microwave systems, power generation is commonly achieved by combining a bunch of transistor amplifier. Regarding the efficiency of power combining operation, insertion loss of the combiner is a critical parameter. In this thesis, several low loss power combiners, namely, microstrip Wilkinson combiner in 6-18 GHz frequency range, suspended stripline branchline couplers in 16.5-17.5 GHz frequency range and finally, planar probe coaxial waveguide combiners in 8.5- 11.5 GHz and 15.5-17.5 GHz frequency ranges are investigated and implemented. It is shown that planar probe coaxial waveguide combiner has much lower loss compared to the other ones. Therefore, 8 identical 2 W power amplifiers are combined using planar probe coaxial waveguide combiners of two different operating frequency bands to get 15 W outputs in both 8-12 and 15-18 GHz frequency ranges successfully.


Design and Performance Analysis of a Grid Connected PWM-VSI System
Kantar, Emre; Usluer, S. Nadir; Hava, Ahmet Masum (2013-11-30)
Pulse-width modulation (PWM) voltage source inverters (VSIs) are favorable interface devices to the power grid for renewable energy systems. This paper deals with the design of the LCL-filter and inverter for the grid-connected VSI. A complete design procedure for both reactive and passive components of LCL-filter is demonstrated with a new iterative approach in selection of the filter inductors. The design process for a two-level VSI is clearly illustrated through an example and the dynamic response is inv...
Development andcharacterization of activated carbon / transition metal phosphide composites for electrochemical capacitors
Köse, Kadir Özgün; Aydınol, Mehmet Kadri (null; 2019-09-11)
Electrochemical capacitors are the energy storage devices based mainly on electrical double layer formation. Their power densities are exceptionally high; however, their energy densities are characteristically low to compete various types of batteries in market. Therefore, there have been great amount of studies to enhance electrochemical capacitors’ energy density. Utilization of inorganic materials such as transition metal oxides and/or phosphides is one of the most common strategies to increase energy de...
Design and implementation of a voltage source converter based statcom for reactive power compensation and harmonic filtering
Çetin, Alper; Ermiş, Muammer; Department of Electrical and Electronics Engineering (2007)
In this thesis, design and implementation of a distribution-type, voltage source converter (VSC) based static synchronous compensator (D-STATCOM) having the simplest converter and coupling transformer topologies have been carried out. The VSC STATCOM is composed of a +/- 750 kVAr full-bridge VSC employing selective harmonic elimination technique, a low-pass input filter, and a /Y connected coupling transformer for connection to medium voltage bus. The power stage of VSC based STATCOM is composed of water-co...
Design and Analysis of PLLs for Line-connected Converters in Three Phase Systems
Vyawahare, D.; Kose, H.; AYDEMİR, MEHMET TİMUR; Chandorkar, M. C. (2011-09-10)
This paper is concerned with phase locked loop (PLL) structures for use in the control of line connected power electronic converters in three phase systems. Such converters have to operate under conditions in which the power system phase voltages are often unbalanced. The unbalanced and distorted line voltage vector as observed in the stationary reference frame generally has instantaneous rates of change components in the radial as well as in the angular directions. The essential task of a PLL in this conte...
Investigation of Self-Excited Ultrahigh Speed Induction Generators for Distributed Generation Systems
Jardan, Rafael K.; Varga, Zoltan; Nagy, Istvan (2011-09-10)
Application of ultra high speed induction generators (IG) in a system developed for utilization of renewable and waste energies that can be applied in Distributed Generation System is presented. The energy conversion is made by a turbine-generator set. For the electromechanical energy conversion application of special high speed induction generators has been studied and described in the paper. The design and analysis of the system are relied on computer simulation techniques verified by test results.
Citation Formats
G. Suna, “Design and realization of high power low loss combiners,” M.S. - Master of Science, Middle East Technical University, 2013.