Effect of feeding symmetry on resonances in patch and capacitor structures

It has been observed that the location of the feed point has a strong influence on the impedance and resonance frequency of patch antennas and capacitors (see Schaubert, D.H. and Yngvesson, K.S., 1986; Murphy, A.T. and Young, F.J., 1995). The cavity model, which is usually applied to describe rectangular patch structures (see Navarro, J.A. and Chang, K., 1996), however, does not account for any feeding symmetry effects. We use FDTD simulations to analyze the resonance modes in patch and capacitor structures with different feeding geometries. It is shown that the symmetry of the feed determines the type of resonance modes observed in the structures, and, hence, the performance characteristics of the device. The obtained results, which provide a clear understanding of the resonance processes in patch and capacitor structures, are very important for device design optimization.