A Multi-Gigabit CPFSK Polymer Microwave Fiber Communication Link in 40 nm CMOS

This paper presents a multi-gigabit communication link over a polymer microwave fiber (PMF). A polymer fiber is a light-weight and low-loss channel at millimeter-wave (mm-Wave) frequencies. PMF is a promising, robust and low-cost technology to complement copper or optical links for high-speed applications with transmission distances up to several meters. The high carrier frequency of 120 GHz ensures low bending losses for small bending radii and features a large absolute bandwidth, which can be exploited to achieve high data rates with a simple modulation scheme. The used continuous-phase frequency shift keying (CPFSK) modulation results in a power-efficient system at both the TX and the RX side. We report on 120 GHz 40 nm bulk CMOS TX and RX chips, the fiber and the coupling solution between the chips and the fiber. Data rates up to 12.7 Gbps over 1 meter, transmission lengths up to 7 meters at 2.5 Gbps and a link energy efficiency of 1.8 pJ/b/m for 4 meters and 7.4 Gbps are achieved for the complete communication link.