Design of Miniaturized Differential Antenna Using Gradient Planar Slow-Wave Structure

A miniaturized differentially-fed patch antenna using gradient planar slow-wave structure (PSWS) is proposed in this paper. Due to the large propagation constant and slow-wave effect of the PSWS combining with the utilization of the coupled shorted patches, the effective size of the antenna is reduced to 0.09
$\lambda_{0}\times 0.1\ \lambda_{0}$
, where
$\lambda_{0}$
is the vacuum wavelength at 2.92 GHz. Simulated results demonstrate that the proposed antenna operates at a simple coupled TM10 mode with excellent cross-polarization levels, which is an attractive candidate in the differential wireless communication systems for portable applications.