60 GHz reference chip antenna for gain verification of millimeter wave test chambers

We have developed a 60 GHz chip antenna designed for use as a gain and pattern verification tool in the calibration process of a millimeter wave antenna test chamber. The antenna is designed to interface with ground-signal-ground (GSG) micro-probes that have a probe pitch of 150 um to 250 um. This low temperature cofired ceramic (LTCC) chip antenna is fabricated using DuPont's 9K7 GreenTape™ material system with gold conductors. Features include a wafer-probe transition, a shielded stripline corporate feed network, aperture coupled patch elements, and an integrated Sievenpiper electromagnetic bandgap (EBG) structure for surface wave mode suppression. The use of the EBG structure enables main beam gain enhancement and side lobe level suppression. This 2×2 antenna array is directive such that it offers a nominal gain of 12 dBi at broadside over 58–62 GHz with an antenna efficiency of at least 60%. The entire antenna package has a nominal size of only 10.9 mm × 12.2 mm × 0.71 mm. Since this antenna package material is hermetic, it has stable performance under varying humidity and temperature which is highly desirable as a reference antenna.