150-GHz-Bandwidth InP-HBT Baseband Amplifier Module With DC-Block Functions

This letter presents a 150-GHz-bandwidth baseband amplifier module with integrated dc-block functions. The baseband amplifier IC was fabricated in 250-nm InP HBT technology with <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${f} _{\mathbf {T}}$ </tex-math></inline-formula>/<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${f} _{\mathbf {max}}$ </tex-math></inline-formula> of 460/480 GHz. The IC itself has a bandwidth of 195 GHz and is mounted on a quartz glass substrate inside the package by flip-chip bonding. The silicon capacitors are also mounted on the same substrate to form dc-block functions for the input/output of the amplifier IC. The assembled baseband amplifier module is equipped with 0.8-mm coaxial connectors, which cover a frequency range up to 150 GHz, for its input/output interfaces, and has a footprint as small as <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$10.0\times 15.4$ </tex-math></inline-formula> mm. The module has a gain of 6.5 dB at a frequency of 1 GHz and a 3-dB bandwidth of over 150 GHz, ranging from 312 kHz to above 150 GHz. The measured output of the 1-dB compression point (OP1 dB) was 9.2 and 8.8 dBm at 50 and 100 GHz, respectively. The ultra broadband baseband signal amplification capability of the module was successfully demonstrated on a 160-GBd four-level pulse-amplitude modulation (PAM-4) signal. To the best of the authors’ knowledge, this is the first demonstration of a 150-GHz-bandwidth baseband amplifier module that has dc-block functions.