Multiband extensions of the electrically small, near-field resonant parasitic Z antenna

Variations of the electrically small, resonant near-field parasitic Z antenna are investigated. By introducing multiple near-field resonant parasitic elements, multiband systems are developed. Simulations reveal how the couplings between these multiple parasitic elements impact their individual internal matching networks and radiation mechanisms. The impact of each configuration on its potential fabrication is taken into account. Dual-band designs are reported that achieve operation at the satellite communication frequency, 430 MHz, at the global positioning satellite (GPS) L1 frequency (1575.42 MHz) and at the GPS L1 and L2 (1227.60 MHz) frequencies. A quad-band design that operates at 430 MHz and at all of the GPS L1, L2 and L5 (1174.45 MHz) frequencies is also reported. The simulated performance characteristics of each design, including their level of matching to a 50 Ω source, their radiation efficiencies, their bandwidths and their radiation patterns are given.