A Differential Wideband Circularly Polarized Laminated Resonator Antenna

This letter reports a differential wideband circularly polarized (CP) laminated resonator antenna (LRA) fed by quadruple L-shaped probes. A pair of 90° power dividers is utilized as the feed network and connected to the adjacent L-shaped probes. By supplying the 90° power divider pair with differential signals, degenerate and orthogonal
$\text{TE}^{\textit{x}}_{011}$
and
$\text{TE}^{\textit{y}}_{101}$
modes of the square LRA can be excited with equal amplitude and 90° phase difference to generate circular polarization. For verification, an antenna prototype is designed, fabricated, and measured. Experimental results demonstrate that the proposed differentially fed CP LRA obtains a wide effective CP bandwidth of 52% in a height of 0.096
λ
₀
. The gain and radiation patterns are stable within the usable bandwidth. The proposed LRA can be directly integrated with differential circuits and owns the widest CP bandwidth among the existing CP LRAs in the open literature.