2021/07/14 by Binbin Yang, Yang, Binbin, Jae-Woo Kim +3
Engineering · #Advanced Antenna and Metasurface Technologies #Microwave Engineering and Waveguides #Antenna Design and Analysis
paper · pdf · doi:10.48550/arxiv.2108.04691
We show theoretically that the characteristic modes of dielectric resonator antennas (DRAs) must be capacitive in the low frequency limit, and show that as a consequence of this constraint and the Poincaré Separation Theorem, the modes of any DRA consisting of partial elements of an encompassing super-structure cannot resonate at a frequency that is lower than that of the encompassing structure. Thus, design techniques relying on complex sub-structures to miniaturize the antenna, including topology optimization and meandered windings, cannot apply to DRAs. Due to the capacitive nature of the DRA modes, it is also shown that the Q factor of any DRA sub-structure will be bounded from below by that of the super-structure at frequencies below the first self-resonance of the super-structure. We demonstrate these bounding relations with numerical examples.