Circularly Polarized Arrowhead-Shape Slotted Microstrip Antenna

A novel single-feed arrowhead-shape slotted microstrip antenna for circular polarization (CP) is proposed. To achieve CP radiation and antenna size reduction, an arrowhead-shaped slot is embedded in the first quadrant along the diagonal axes of a square patch. Thus, the structure is asymmetric, and good-quality CP performance can be achieved by adjusting the size of the slot. The antenna is simulated and practically fabricated. Measured results confirm the validity of this design and show a good agreement with simulated results. The antenna generates CP radiation at 911 MHz with an overall size of 87 × 87 × 4.572 mm ³. The fabricated antenna shows an impedance bandwidth of 35.0 MHz (888.0-923.0 MHz) with 8.0 MHz (908.0-916.0 MHz) 3-dB axial-ratio bandwidth (ARBW).