1.4-THz gain-bandwidth product InP-HEMTs preamplifier using an improved Cherry-Hooper topology

We have developed an InP-HEMT differential-ended broadband preamplifier with THz-class gain-bandwidth product by using an improved Cherry-Hooper topology. The key to achieving the high performance preamplifier is to use a mismatching technique, which expands the impedance difference between gain stages. Using this technique, we achieved 64 dB/spl Omega/ transimpedance gain with a 40 GHz bandwidth, and its gain-bandwidth product reached 1.42 THz - the highest yet reported for 40 Gbit/s preamplifiers.