Analog Circuit Blocks for 80-GHz Bandwidth Frequency-Interleaved, Linear, Large-Swing Front-Ends

Abstract

Critical analog electronic circuits for a possible 80-GHz bandwidth, frequency-interleaved, PAM-4 or discrete-multitone (DMT) linear fiber-optic front-end are implemented in a 90-nm SiGe BiCMOS technology. These include a novel vertically coupled, 40–100-GHz bandpass filter, an 80-GHz bandwidth distributed optical modulator driver with a measured output compression point of 13 dBm per side, corresponding to 7 $\text{V}_{\mathrm {pp}}$ output differential swing, and a 125-GHz bandwidth PIN-diode SPST switch with a OP $_{1{-}\mathrm {dB}}$ of 23 dBm, and over 22 dB of isolation up to 160 GHz. The linear modulator driver can also be used as a high linearity (IP $_{1{-}\mathrm {dB}} = \,\, 5$ dBm per side) receiver amplifier in next-generation instrumentation systems.