Communication between integrated circuits, such as the CPU and peripheral blocks, occurs over a high-speed bus, which requires physical wire traces on a printed circuit board. In most mobile computing and communication platforms, such as a smart phone or tablet, the form factor is constrained by the requirement to connect to this bus. We propose a sub-THz (~300 GHz) wireless bus that eliminates this constraint, allowing integrated circuits to be placed anywhere inside of the device with communication links established wirelessly and automatically. New circuit, antenna, and system architectures will be explored to enable an energy efficient realization of the key components of such a system. Two prototypes at 240 GHz and 360 GHz will demonstrate the feasibility of the proposal.
Intellectual Merit: The described technology could have tremendous impact on the design of a new generation of ultra thin and small devices, allowing chips to be placed in the most optimal positions, either to increase the aesthetics of the design or enable better engineering. The link is established using the sub-THz frequency spectrum (~300 GHz) using on-chip electronics and antennas in standard CMOS technology. To be competitive with the wired links, the link must be extremely energy efficient and must not occupy a bigger footprint on the silicon die than existing systems. Antennas at sub-THz frequencies are in fact extremely small and can be comparable in size to traditional bonding pads, which are used to connect to the physical traces. Moreover, due to the large carrier frequency, only modest fractional bandwidth is needed to support high throughputs using simple modulation schemes.
Broader Impacts: Wireless communication is a rapidly growing field and its importance to the national economy cannot be overstated. While in the previous decades the semiconductor industry was driven largely by the digital microprocessor market, today the combination of high performance computation on a portable device combined with voice and data communication is the major driver. This research is intended to advance the state of ?smart? phones, tablets, and ultra-portable laptops. A wireless chip-to-chip communication channel, or a wireless bus, will enable integrated circuits to be minimized (by removing IO pads/pins), allow the board real-estate to be used with increased flexibility, reducing the number of planes in the printed circuit board and reduce the required amount of waste.
