A 60GHz on-chip RF-Interconnect with λ/4 coupler for 5Gbps bi-directional communication and multi-drop arbitration

A 5Gbps bi-directional RF-Interconnect (RF-I) with multi-drop and arbitration capabilities is designed and realized in 65nm CMOS. The baseband data are modulated in RF-I by using a 60GHz carrier in ASK format. An on-chip differential transmission line (TL) is used as the communication channel, which minimizes the latency (9ps/mm) only under the speed-of-light limitation. We insert λ/4 directional couplers for implementing multi-drops without signal reflection. We also use MOS switches along the signal path to reconfigure/arbitrate communication priority for multi-drops. This design consists of four TX/RX drops along a 5.5mm TL ring, supports destructive reading with fixed priority, and can reconfigure any drop as the transmitter. The tested data rate of the RF-I is 5Gbps with lower than 10^-12 BER. The average power consumptions for the link are 1.33pJ/b and 0.24pJ/b/mm.