A low droop rate wide input bandwidth high dynamic range track-and-hold amplifier is proposed using 0.18 um SiGe process in this paper. A master-slave track-and-hold topology is employed in the circuit design to further enhance the hold-mode isolation, and the measured droop rate is lower than 6 uV/ps. A distributed amplifier is adopted for the input buffers and the clock buffers to widen the input bandwidth and sampling speed. Moreover, a differential feedthrough cancellation technique is employed in the track-and-hold stage to enhance isolation and linearity. With a total dc power consumption of 134 mW, the proposed THA features an input bandwidth of 10 GHz and an isolation of more than 50 dB. The measured spurious free dynamic range is 39.2 dB when the sampling rate is 7 GS/s.