A Compact Broadband Circular Polarization Slot Antenna with Coplanar Waveguide Feeding

A novel compact broadband circular polarization (CP) slot antenna with coplanar waveguide feeding is proposed. There is a slot which consists of two semicircular annular distributed symmetrically on either side excited to radiate. In addition, the use of coplanar waveguide (CPW) feeds facilitates the integration and application of arrays. The measured result of wide antenna impedance bandwidth for
$\vert \mathrm{S}_{11}\vert < -10\ \text{dB}$
is from 4.4 GHz to 8.5 GHz, and the measured result of wide axial ratio (AR) bandwidth for
$\text{AR} < 3\ \text{dB}$
is from 4 GHz to 7.4 GHz. Besides, the antenna is an LHCP antenna which can provide more than 3dB LHCP Gain at 5GHz to 8GHz. The measured results are very similar to the simulated results. The structure of antenna is very compact and low profile, and the final overall size of antenna is only
$40\text{mm}\times 40\text{mm}\times 1.6\text{mm}$
.