Vincent G. Harris
Carmine Vittoria, Katherine S. Ziemer
Date of Award
Master of Science
Department or Academic Unit
College of Engineering. Department of Computer and Electrical Engineering
electrical engineering, microstripline, microwave devices, phase shifters, Yttrium Iron Garnet (YIG)
Electrical and Computer Engineering | Engineering
Microstripline phase shifters, fabricated using thick YIG films, have been described previously and are suitable for a wide range of microwave applications. Earlier designs using ferrite phase shifters require a few thousands of Oersteds magnetic field to produce usable large phase changes (ΔΦ) and suffer from disadvantages of large size and weight. This research aims to fabricate a planar microstripline phase shifter that is compact and light weight using bulk Yttrium Iron Garnett (YIG) material. It is capable of producing large differential phase change (ΔΦ) for very small applied field thus eliminating the need for heavy permanent magnets. YIG material possesses narrow FMR linewidth and low insertion loss at C band frequencies. The propagation direction of the microstrip and magnetization direction of the YIG is collinear, and the length of the microstrip and the YIG is ~5 cm in length.
The proposed design shows large differential phase changes of 100 degrees for applied magnetic fields from 0 to 5.57 kA/m (70 Gauss) over the frequency range of 1.2 GHz between 5.4 GHz and 6.6 GHz. The average insertion loss, ~0.8 dB, was measured to have a bandwidth of ~ 1.2 GHz. This work also evaluates the effect of YIG material thickness on the phase shift and insertion loss properties of the phase shifter device. The planar phase shifter presented here demonstrates a compact design, low loss, and an especially large phase shift with a relatively small bias field. This design is particularly well-suited for future microwave and millimeter wave devices applications in which light-weight and high performance are required.
Viswanathan, Ilancheliyan, "High performance compact microstripline phase shifter at C-band using Yttrium Iron Garnet" (2009). Electrical and Computer Engineering Master's Theses. Paper 35. http://hdl.handle.net/2047/d20000836
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