Disc-Loaded, Vertical Top-Hat Monopole Antenna at 225 GHz for On-Chip Wireless Communications

The challenges of intra- and inter-chip wireless communication arise from the very small electrical thickness of the silicon dioxide and from the direction of the main beam of the antenna. In most of these cases the antennas are placed horizontally on the substrate with the radiation orthogonal to the plane of the chip which results in low transmission in the plane of the chip. A vertical monopole has the desired radiation pattern but becomes electrically small which, in turn, makes the input impedance highly capacitive. Furthermore the silicon substrate reduces the radiation resistance. To address these issues, the present work presents a vertical top-hat monopole placed in silicon dioxide (SiO₂) as the wireless interconnect. It has a ground plane in the shape of a disc to improve the radiation resistance. Matching is achieved by the top-hat that provides a capacitance and a shorting post connecting the top-hat to the grounded disc which provides an inductance. The results for impedance matching and the radiation pattern obtained through simulations are encouraging. To increase the radiation efficiency, it is design trade-off with the silicon dioxide substrate thickness.