A high bandwidth 11-bit 1.5GS/s track and hold amplifier in 0.25 µm SiGe BiCMOS

The paper describes a Track and Hold Amplifier suitable for high-speed and high resolution applications like Software Defined Radios. Thanks to the adopted techniques to maximize the resolution without reducing the sampling frequency, all the non idealities limiting the equivalent number of bits have been taken into account. In particular a novel technique to reduce the third harmonic distortion has been proposed and exploited. Post-layout simulations show that the performances are quite constant and the linearity is compatible with 11-bit (SFDR) at F
_s
= 1.5GS/s up to a frequency 1GHz.