Trends and outlook of wireless I/O's for short-range connectivity and beyond

The increasing need for extremely high I/O bandwidth in multi-chip or multi-core systems have driven researchers to look beyond the traditional use of wireline for interconnection. Both RF/wireless and optical interconnects within a chip have been explored to potentially address this challenge. In the case of optical interconnect, the manufacturing cost and integration compatibility with CMOS remain to be the bottleneck. In this paper, the practical application and challenge of wireless I/O's for chip-to-chip communication is examined. A key advantage of wireless I/O's is its usage flexibility. A review of previously reported wireless techniques for proximity connectivity is presented. In addition to low-power RF transceivers, on-chip antenna with small footprint and low loss is the key to enable wireless I/O's as an alternative, or a complementary, to wireline interconnects in future systems.