A 120 GS/s 2:1 Analog Multiplexer with High Linearity in SiGe-BiCMOS Technology

A 2:1 analog multiplexer (AMUX) in SiGe BiCMOS technology with a record sampling rate for SiGe-technology of 120 GS/s, is presented. The AMUX is intended to double the signal bandwidth of two 8-bit digital-to-analog-converters and achieves an effective resolution (ENoB) of 7.7 bit, at low frequencies as well as 5.1 bit at 48.8 GHz and 4.1 bit at 58.6 GHz for sampling rates of 100 GS/s and 120 GS/s, respectively. These are the highest resolutions reported for an AMUX in any kind of semiconductor technology. The results were obtained by a simple selector-circuit concept that was carefully optimized in the frequency domain with regard to balanced signal paths. The AMUX performance was demonstrated by measurements on an RF-module bondwire-assembly of the AMUX-chip.