Analysis, modelling, and design of microwave planar ferrite devices and antenna circuits using spectral domain method of moments

The objective of this research is to develop the theoretical and numerical models, based on the method of moments, for the analysis of various ferrite microwave devices and antenna circuits. The transmission matrix for a normally biased ferrite layer is derived in a closed form. The Green's function is formulated using the transmission matrix. A 2-D model is implemented to analyze the edge-guided mode microstrip isolator. The resistive film termination over one edge of the microstrip, to absorb the backward wave, is considered in this work. The closed form transmission matrix for any arbitrarily biased ferrite slab is also derived to formulate a very general Green's function for multi-layer arbitrarilly magnetized ferrite structures. Two numerical models are implemented: phase shifter model and a magnetostatic surface wave model. Good agreement with the previously published results is achieved. A novel approach to analyze scattering from arbitrarily shaped patches on arbitrarily biased ferrite substrates is presented. In that approach, the excitation vectors for various single and multi-layer antenna structures are derived in a closed form using the transmission matrix. A 3-D model is implemented to study the Radar Cross Section (RCS) for several ferrite antennas. A novel cross patch antenna is proposed which results in significant RCS reduction.