Simulation of Single-Arm Fractional Spiral Antennas for Millimeter Wave Applications

In this paper, a planar single-arm fractional spiral antenna for millimeter wave applications is proposed. Outer-fed by microstrip line, the antenna is printed on a planar PCB with a circular aperture on the ground plane. The antenna design is illustrated with a 5 mil-thick RO5880 substrate with a circular aperture of diameter 3.7 mm operating at 44 GHz. Promising results are achieved, including the 10 dB return loss bandwidth of 35%, the 3 dB axial ratio bandwidth around 20%, and the antenna gain of 2.6 to 3.9 dBic in the 40 to 48 GHz band