Date of Award
Doctor of Philosophy (PhD)
Electrical and Computer Engineering
Laurie L. Joiner
John D. Williams
Robert G. Lindquist
Sivaguru S. Ravindran
Patrick J. Reardon
Phase shifters., Phased array antennas., Ferrite devices.
As the demand for smaller size, lighter weight, lower loss and cost of communications transmit and receive (T/R) modules increases, there is an urgent need to focus investigation to the major subsystem or components that can improve these parameters. Phase shifters contribute greatly to the cost of T/R modules, and thus this research investigation examines a new way to reduce the weight and cost by miniaturizing the phaser design. Characterization of hexaferrite powders compatible with the sequential multilayer micro-fabrication technology and numerical simulations of a novel rectangular micro-coaxial phase shifter are investigated. This eort aims to integrate ferrite material into a rectangular micro-coaxial waveguide at Ka-band using electromagnetic nite element numerical tools. The proposed technique exploits rectangular coaxial waveguide with a symmetrically placed inner signal conductor inside an outer conductor connected to the ground. Strontium ferrite-SU8 composite is used as an anisotropic material of choice in the modelled design. Numerical modeling is employed using High Frequency Structure Simulator, HFSS, a 3-D full wave electromagnetic solver for analyzing the performance of the device. Two model structures were designed for reciprocal and non-reciprocal applications. The rst model (Model A) produced a tunable phase shift of almost 60 degrees /cm across 0 to 400 kA/m applied eld and at 1800 Gauss. In model B, a non-reciprocal phase shift performance of 20 degrees /cm from a reference phase of 24 degrees at 0 A/m was realized at the same saturation magnetization. A return loss better than 20 dB and an insertion loss less than 1.5 dB were obtained for both models.
Sholiyi, Olusegun Samuel, "Electromagnetic characterization of photo-definable ferrite loaded polymers and their applications in micro-rectangular coaxial phase shifters" (2014). Dissertations. 45.