A 20-Gs/s Track-and-Hold Amplifier in InP HBT Technology

This paper presents a 20-Gs/s track-and-hold amplifier (THA) fabricated InP HBT technology. This THA is capable of operating under relatively high input voltages. The THA uses a fully differential architecture with a switched emitter–follower. To mitigate the pedestal error due to the feedthrough attenuation network, we added degeneration resistors in the feedthrough attenuation block. Measured total harmonic distortion is below
$-{\hbox{40 dB}}$
at low input frequencies, and
$-{\hbox{18 dB}}$
at frequency of 9.9 GHz.