60 GHz Resonant Photoreceiver With an Integrated SiGe HBT Amplifier for Low Cost Analog Radio-Over-Fiber Links

An analog radio-over-fiber photoreceiver based on a resonant narrowband transimpedance low noise amplifier (TILNA) is proposed and demonstrated for use in low-cost and low-power remote radio heads for distributed antenna systems in the unlicensed 60 GHz band. The amplifier is designed to present a conjugate matched impedance to a wirebonded photodiode where the input impedance has a real part of 10Ω while the output impedance is matched towards 50 Ω. Fabricated in a 55 nm SiGe BiCMOS technology, the TILNA features a three stage common emitter low noise amplifier with 17 dB of gain, a 3.4 dB noise figure, an output 1-dB compression point of 8 dBm and low power consumption of 33.6 mW while occupying only 0.25 mm
²
of chip space including pads. The photoreceiver, formed by the TILNA and a wirebonded InP UTC photodiode, offers 29 dB higher gain than a 50 Ω terminated reference photodiode where 11 dB improvement is provided by resonant matching. Experimental results show that the proposed photoreceiver has achieved up to 20Gbps C-band transmission of complex modulated waveforms over 5km of standard single-mode fiber using 4 Gbaud QAM32 with an RMS EVM of 11.5%.