Low Distortion 50 GSamples/s Track-Hold and Sample-Hold Amplifiers

We report 50 GSamples/s track-hold amplifier (THA) and sample-hold amplifier (SHA) designed and fabricated in a 250 nm InP double heterojunction bipolar transistor (DHBT) technology. Because the base-emitter junction reverse breakdown voltage is low in the process technology employed, the circuits use a base-collector junction diode as the switching element in the signal path. Operating with -5 V and -2.5 V supplies, the THA achieves > +16 dBm input-referred third-order intercept (IIP3) at signal frequencies below 22 GHz, while the SHA achieves IIP3 > +17 dBm for 2-22 GHz inputs.