Analysis and Design of a 7 Gb/s Rotatable Non-contact Connector with Grid Array Package Application

A 7 Gb/s compact rotatable transmission line coupler (RTLC) is developed for grid array applications and is suitable for high-speed multi-pin FPGA packages. The miniaturized RTLC operates in a new deep proximity coupling mode, achieving high coupling gain and wide bandwidth simultaneously. Ground shielding vias provide return paths for signal vias, which achieves better impedance matching and suppresses signal reflection to 1/18. Following miniaturization, a prototype of a 4x4 grid array with a pitch of 1 mm is fabricated. In terms of crosstalk performance, the RTLC-grid array exhibits robustness against horizontal offsets of up to 10% of the pitch and vertical offsets of up to 33% of the communication distance, even under the most severe conditions.