Wideband Compact Circularly Polarized Monopole Printed Antenna

A compact wideband circularly polarized printed monopole antenna is designed here. This wide circular polarization (CP) performance is achieved by using a rectangular microstrip monopole and a defected ground plane. The defection in the ground plane involves creating short vertical and horizontal open slots on the ground plane and adding a small vertical extension. The achieved results depict an $\left|S_{11}\right| \leq-10 \mathrm{~dB}$ bandwidth of $\mathbf{3. 9 - 9} \mathbf{~ G H z}(\mathbf{7 9 \%})$ and an $\mathrm{AR} \leq 3 \mathrm{~dB}$ bandwidth of $5.1-8.9 \mathrm{GHz}(55 \%)$. Antenna dimensions is 25 mm $\times 25 \mathrm{~mm}$. This design is easy to fabricate and optimize and does not require complex parasitic elements or complex monopole structures to generate CP. CP generation based on eigenmodes is studied by characteristic mode analysis (CMA). At the symposium, details of the design procedure, gain and radiation pattern characteristics, and comparison to previous works will be exhibited.