A 5–50 GHz SiGe BiCMOS Linear Transimpedance Amplifier with 68 dBΩ Differential Gain towards Highly Integrated Quasi-Coherent Receivers

Abstract

Quasi-coherent optical receivers have recently emerged targeting access networks, offering improved sensitivity and reach over direct-detection schemes at the expense of a higher receiver bandwidth. Higher levels of system integration together with sufficiently wideband front-end blocks, and in particular high-speed linear transimpedance amplifiers (TIAs), are currently demanded to reduce cost and scale up receiver data rates. In this article, we report on the design and testing of a linear TIA enabling high-speed quasi-coherent receivers. A shunt-feedback loaded common-base topology is adopted, with gain control provided by a subsequent Gilbert cell stage. The circuit was fabricated in a commercial 130 nm SiGe BiCMOS technology and has a bandpass characteristic with a 3 dB bandwidth in the range of 5–50 GHz. A differential transimpedance gain of 68 dBΩ was measured, with 896 mVpp of maximum differential output swing at the 1 dB compression point. System experiments in a quasi-coherent receiver demonstrate an optical receiver sensitivity of −30.5 dBm (BER = 1 × 10−3) at 10 Gbps, and −26 dBm (BER = 1 × 10−3) at 25 Gbps. The proposed TIA represents an enabling component towards highly integrated quasi-coherent receivers.

A 130-to-220-GHz Frequency Quadrupler with 80 dB Dynamic Range for 6G Communication in 0.13-μm SiGe Process

“…Compared to GaAs and GaN processes, the SiGe BiCMOS technologies are capable for higher integration and lower power consumption, which is crucial for portable devices with compact size. Various solid-state circuits have been implemented in SiGe technologies [1][2][3][4], such as the CML divider (Current Mode Logic divider) [5], transimpedance amplifier [6], voltage-controlled oscillators (VCOs) [7], bandpass filter [8], and switch [9]. Including the above various blocks based on the SiGe BiCMOS process, they have been widely used in various sub-THz systems, including radar receivers [10], 5G transceiver [11], and high-resolution imaging device [12].…”