An Integrated Wide-Band Circularly Polarized Antenna for Millimeter-Wave Applications

This communication describes the design, integration and measurement of a compact, wide-band, circularly polarized antenna for millimeter-wave short-range communication. The antenna is comprised of a five-section square loop and a tapered feed line. This configuration is less sensitive to the fabrication issues compared to the conventional circular spiral antennas. Two samples of this antenna designed for 60 GHz are integrated in a 6 layer IC package. The measured impedance bandwidth of the antenna-in-package is over 12 GHz. Moreover, this circularly polarized antenna provides over 7 GHz of axial ratio bandwidth. The measured peak gain is around 6 dBi. The compact-size and simple feed structure of the designed antenna make it a low-cost solution for the integrated millimeter-wave radio packaging.