Farhan Abdul Ghaffar's paper on ferrite LTCC phase shifter has been published in the IEEE transactions of magnetics. The paper reported for the first time theory and design of a Ferrite LTCC based half mode SIW phase shifter in a partially magnetized state.
Abstract- The theory and design of a half mode SIW ferrite LTCC based phase shifter is presented in this work. Unlike typical ferrite based designs, the biasing is done through embedded windings in a multilayer substrate which not only obviates the requirement of bulky electromagnets but also prevents loss of bias fields at the air-to-ferrite interface. The phase shifter is operated in the partially magnetized state of the ferrite substrate. Through the combined effect of embedded windings, half mode waveguide operation and partially magnetized state, the required bias fields have been reduced by 90% as compared to conventional ferrite based designs employing electromagnets. A complete analytical model backed up by electromagnetic simulations and measured results from a prototype is presented in this paper. The fabricated prototype demonstrates a phase shift of 83.2° at a center frequency of 13.1 GHz and a figure of merit of 83.2°/dB. As a proof-of-concept, the proposed phase shifter design is monolithically integrated with a two-element antenna array to demonstrate a measured beam steering of 30°. The phase shifter design is highly efficient in terms of required bias fields, has a small form factor and can be easily integrated with other electronic components and systems.
