Wireless Inter-Chip Signal Transmission by Electromagnetic Coupling of Open-Ring Resonators

Low loss and wide bandwidth wireless signal transmission structure between IC chips is realized with electromagnetic coupling of open-ring resonators. Open-ring resonators are placed on separate sapphire substrate and they are stacked, then, microwave signals with the resonant frequencies are passed to the other resonator through sapphire substrate. With 960 µm diameter rings, 18 GHz band signals are transmitted through 200 µm sapphire substrate. The transmission losses were only -1.54 dB and the bandwidth was 4.8 GHz wide. Since the structure is simple and insensitive to misalignments, the structure will be conveniently used for wireless or non-contact signal transmission for short distances.