Fabrication of antennas on a thick resin layer fed through a hole from the bottom in a silicon chip at 60GHz

We proposed a dipole antenna integrated on a thick resin layer on the opposite side of a RF circuit layer though a hole in a silicon CMOS chip at 60 GHz. The thick resin layer can enhance the radiation efficiency. The connection loss between the antenna and the RF circuit is expected to be small. In this paper, we modify the opening of the holes by drilling to achieve smoother walls and reduce the size of the hole in the resin and in the silicon. In the 5 mm-square chip for the dipole antenna, the hole diameter in the resin can be reduced to 0.2 mm and the hole size in the silicon can decrease to 0.9 mm × 0.6 mm. The measured gain is almost unchanged (about 4 dBi). Also, we discuss another configuration of coaxial-line feed to a patch antenna.