Research

Millimeter-wave antenna-embedded package/module developement

A multilayer organic package with embedded 60-GHz antennas and fully integrated with a 60-GHz phased-array TX or RX chip is demonstrated for the first time in the world. The package includes 16 phased-array antennas, an open cavity for housing the flip-chip attached RF chip, and interconnects operating at DC-66 GHz. The 28 mm x 28 mm BGA package is manufactured using low-cost PCB process and uses a combination of liquid-crystal polymer and glass-reinforced laminates, allowing excellent 60-GHz interconnect and antenna performance. We have also developed 77-GHz automotive radar modules and 94/140-GHz imaging modules.

System-level signal integrity analysis

What package improvements are required for dense, high-aggregate bandwidth buses running at data rates beyond 10 Gb/s per channel, and when might optical interconnects on the board be required? We performed a study of distance and speed limits for electrical on-board module-to-module links with an eye to answering these questions. A wide variety of high-performance links has been analyzed from a holistic standpoint, considering I/O circuits and equalization, and including all levels of electrical packaging. Hardware-validated models of advanced organic modules and PCBs allowed us to explore the effect of equalization and modulation formats at different data rates on link performance. Electrical signaling limits were then determined by extrapolating these hardware-correlated models to higher speeds, and these limits were compared to the results of recent work on on-board optical interconnects.