A 24-Gsps 3-bit Nyquist ADC using InP HBTs for electronic dispersion compensation

A 3-bit flash analog-to-digital converter (ADC) for electronic dispersion compensation (EDC) was developed using InP HBTs. Nyquist operation was developed using InP HBT. Nyquist operation was confirmed up to 24 Gsps, which enables oversampling acquisition for 10 Gbits/s nonreturn-to-zero (NRZ) signals. The ADC can also be operated at up to 37 Gsps for low input frequencies. To reduce aperture jitter and achieve a wideband of over 7 GHz, an analog input signal for all latched comparators are provided as travelling waves through coplanar transmission lines.