Physical Bounds and Optimal Currents on Antennas

Antenna Bandwidth Optimization With Single Frequency Simulation

“…This resonance was compared with the corresponding resonance of the input impedance obtained from the commercial solver Eeld. The optimization-predicted and impedance self-resonance agree to a large extent, conrming the validity of the expressions in [4,10,11,24].…”

“…These structures may take arbitrary shapes within a rectangular region with the length l and width h. In order to limit the arbitrariness to a nite set of possible solutions, a discretization rule is established following the approach in [8,10]. The natural choice is to use the same discretization as in the MoM solver used to determine the electromagnetic solution.…”

“…The performance of the structures considered here has been compared with the physical bounds for rectangular structures [6,9,10], and structures with a rectangular ground plane [8]. This comparison shows that the optimized structures perform close to their physical bounds.…”

“…We assume the studied antennas are electrically small, i.e., Q 1, such that the error in the Q computation is negligible (equal to ka 1 [11]). The previously introduced computation is performed following the procedure in [8,10], at a single frequency, usually the center of the intended operating band. Considering the input impedance of antennas described by a resonance model [7,26], the Q factor can be used as a direct measure of the bandwidth.…”

“…Considering the input impedance of antennas described by a resonance model [7,26], the Q factor can be used as a direct measure of the bandwidth. This approach for computing the Q factor is implemented in a standard Method of Moments (MoM) code [8,10].…”