A 5.5Gb/s 5mm contactless interface containing a 50Mb/s bidirectional sub-channel employing common-mode OOK signaling

High-volume, mm-range, contact-less interfaces between modules, which would replace existing interfaces that use wire harnesses and connectors, are expected to be employed in many applications because they would provide such features as immunity to mechanical failures due to vibration/friction, isolation from water/chemicals, and lower fabrication costs. Such conventional radio-wave techniques as UWBs or mm-waves that have been optimized for communication at distances greater than 1cm would suffer from inefficiency in power performance compared with wireline communications. This paper introduces proximity communication using a coupler-in-package that provides a wide-band channel between modules. The relatively large coupler-size in our coupler-in-package permits communication distances to be 1cm or less, while conventional techniques for communication between stacked chips [1,2] have communication distances of less than hundreds of μm. The wideband channel enables baseband communication between chips to support Gb/s-range data transfer with power efficiency comparable to that of conventional wireline transceivers.