Answers are grounded in this paper and cite their sources.
A single-feed dual-frequency microstrip patch antenna that can produce dual circular polarisations (CP) is presented. The microstrip antenna has an annular-ring patch and is excited by an L-shaped microstrip line through the coupling of a ring slot in the ground plane. The occurrence of the dual CP is because the magnetic currents circulating along the ring slot at two specific frequencies have opposite flowing directions. Both simulated and measured results are provided to validate the CP performance of the proposed antenna.
No takes yet. Share an insight, caveat, or question.
Cai et al. (2006) studied this question.
Synapse has enriched 10 related papers. Consider them for comparative context: