Wideband L-Shaped Circular Polarized Monopole Slot Antenna

A wideband circularly polarized L-shaped monopole slot antenna with a single C-shaped feed is designed and fabricated. The measured results demonstrate that the antenna has an axial ratio (AR)<; 3dB, a reflection coefficient <; -10dB, and 23% circular polarization (CP) bandwidth. The monopole quarter-wavelength slot antenna design occupies half of the area on the corner of circuit board as compared to a half-wavelength slot antenna that requires double the area at the center of the board. This feature is attractive for compact wireless devices that operate at low frequencies in which planning for the smallest circuit board area combined with the shortest length for signal routing are the two major concerns. The antenna is extremely low-cost and does not require any truncation corner, reflector surfaces, or via connections, all of which increase the fabrication cost.