Analog I/Q FIR Filter in 55-nm SiGe BiCMOS for 16-QAM Optical Communications at 112 Gb/s

We propose a novel implementation of a complex analog equalization filter for the compensation of frequency-dependent variations in coherent optical links. The analog compensation filter can be used in coherent-lite optical communication links where digital signal processing (DSP) is removed to limit the complexity and power consumption. In these links, the filter can compensate for electrical bandwidth limitations and distortion introduced by chromatic dispersion in the fiber. The complex filter is implemented by combining four distributed analog finite-impulse response (FIR) filters to obtain the necessary response. The filter delays are implemented using active delay cell structures to create a compact solution. The analog filter is implemented in a 55-nm BiCMOS technology and consumes 185-mW core power for five complex filter taps. Performance is evaluated using the S-parameter measurements, noise and linearity measurements, and real-time system experiments using 112-Gb/s 16-QAM-modulated signals.

[1]  Eslam El-Fiky,et al.  DSP-free 'coherent-lite' transceiver for next generation single wavelength optical intra-datacenter interconnects. , 2018, Optics express.

[2]  Matteo Bassi,et al.  Analysis and Design of a Power-Scalable Continuous-Time FIR Equalizer for 10 Gb/s to 25 Gb/s Multi-Mode Fiber EDC in 28 nm LP CMOS , 2014, IEEE Journal of Solid-State Circuits.

[3]  Shalabh Gupta,et al.  Analog Processing Based Equalizer for 40 Gbps Coherent Optical Links in 90 nm CMOS , 2012, 2012 25th International Conference on VLSI Design.

[4]  Matteo Bassi,et al.  A 25mW Highly Linear Continuous-Time FIR Equalizer for 25Gb/s Serial Links in 28-nm CMOS , 2017, IEEE Transactions on Circuits and Systems I: Regular Papers.

[5]  Davide Guermandi,et al.  An up to 36 Gbps Analog Baseband Equalizer and Demodulator for mm-Wave Wireless Communication in 28 nm CMOS , 2016 .

[6]  Xin Yin,et al.  A 106-Gb/s PAM-4 Silicon Optical Receiver , 2019, IEEE Photonics Technology Letters.

[7]  Joseph M. Kahn,et al.  Design of Low-Power DSP-Free Coherent Receivers for Data Center Links , 2018, Journal of Lightwave Technology.

[8]  Michael M. Green,et al.  An 80 mW 40 Gb/s 7-Tap T/2-Spaced Feed-Forward Equalizer in 65 nm CMOS , 2010, IEEE Journal of Solid-State Circuits.

[9]  Davide Guermandi,et al.  An up to 36Gbps analog baseband equalizer and demodulator for mm-wave wireless communication in 28nm CMOS , 2017, 2017 IEEE Custom Integrated Circuits Conference (CICC).

[10]  G. Agrawal.  Fiber‐Optic Communication Systems , 2021 .

[11]  Shuhei Yamada,et al.  A 60-GHz Transceiver and Baseband With Polarization MIMO in 28-nm CMOS , 2018, IEEE Journal of Solid-State Circuits.

[12]  Heng Zhang,et al.  29.2 A transmitter and receiver for 100Gb/s coherent networks with integrated 4×64GS/s 8b ADCs and DACs in 20nm CMOS , 2017, 2017 IEEE International Solid-State Circuits Conference (ISSCC).

[13]  G. Torfs,et al.  Real-Time 100 Gb/s NRZ and EDB Transmission With a GeSi Electroabsorption Modulator for Short-Reach Optical Interconnects , 2018, Journal of Lightwave Technology.

[14]  Govind P. Agrawal,et al.  FIBER-OPTIC COMMUNICATION SYSTEMS Fourth Edition , 2013 .

[15]  Boris Murmann,et al.  A 0.003 mm2 5.2 mW/tap 20 GBd inductor-less 5-tap analog RX-FFE , 2016, 2016 IEEE Symposium on VLSI Circuits (VLSI-Circuits).

[16]  Michiel Verplaetse,et al.  Adaptive Transmit-Side Equalization for Serial Electrical Interconnects at 100 Gb/s Using Duobinary , 2017, IEEE Transactions on Circuits and Systems I: Regular Papers.

[17]  E. Sackinger,et al.  Broadband Circuits for Optical Fiber Communication , 2005 .

[18]  Eric A. M. Klumperink,et al.  Compact Cascadable g m -C All-Pass True Time Delay Cell With Reduced Delay Variation Over Frequency , 2015, IEEE Journal of Solid-State Circuits.

[19]  Chih-Kong Ken Yang,et al.  Power Optimized ADC-Based Serial Link Receiver , 2012, IEEE Journal of Solid-State Circuits.

[20]  Chih-Kong Ken Yang,et al.  ADC-based serial I/O receivers , 2009, 2009 IEEE Custom Integrated Circuits Conference.

[21]  A.C. Carusone,et al.  A CMOS finite impulse response filter with a crossover traveling wave topology for equalization up to 30 Gb/s , 2006, IEEE Journal of Solid-State Circuits.

[22]  Arvind Kumar Mishra,et al.  First demonstration of an all analog adaptive equalizer for coherent DP-QPSK links , 2017, 2017 Optical Fiber Communications Conference and Exhibition (OFC).

[23]  William Shieh,et al.  End-to-End Energy Modeling and Analysis of Long-Haul Coherent Transmission Systems , 2014, Journal of Lightwave Technology.

[24]  Elad Alon,et al.  Design Techniques for a Mixed-Signal I/Q 32-Coefficient Rx-Feedforward Equalizer, 100-Coefficient Decision Feedback Equalizer in an 8 Gb/s 60 GHz 65 nm LP CMOS Receiver , 2014, IEEE Journal of Solid-State Circuits.

[25]  Raimondo Caprio.  Precision differential voltage--current convertor , 1973 .

[26]  Gunnar Jacobsen,et al.  Chromatic dispersion compensation in coherent transmission system using digital filters. , 2010, Optics express.

[27]  Qing Zhang,et al.  A 31.5-GHz BW 6.4-b ENOB 56-GS/s ADC in 28nm CMOS for 224-Gb/s DP-16QAM coherent receivers , 2018, 2018 IEEE Custom Integrated Circuits Conference (CICC).

[28]  Shalabh Gupta,et al.  Analog Domain Signal Processing-Based Low-Power 100-Gb/s DP-QPSK Receiver , 2015, Journal of Lightwave Technology.