Design and realization of high power low loss combiners

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Thesis Type: Postgraduate

Institution Of The Thesis: Orta Doğu Teknik Üniversitesi, Faculty of Engineering, Department of Electrical and Electronics Engineering, Turkey

Approval Date: 2013

Student: GONCA SUNA

Co-Supervisor: ŞİMŞEK DEMİR, NEVZAT YILDIRIM

Abstract:

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.