Research on ultra-small millimeter-wave wireless terminal

Since the silicon substrate has a low resistivity (10 Ω cm), the radiation efficiency is about 10% or less. In this research, we investigated a high-efficiency on-chip antenna using the technology of ion irradiation of hydrogen or helium onto a silicon substrate and through silicon vias. Radiation efficiencies of 50% and 52% were obtained by simulation in the 60 GHz band on-chip antenna assuming bonding wire and flip-chip packaging, respectively. In preparation for the actual chip prototype, we research the simulation technology in packaging technologies and connection of each circuit in the chip to simulate the electromagnetic field required not only for the on-chip antenna but also for the evaluation of the digital/analog mixed circuit.