WR-3.4 InP HBT Amplifier Module With Integrated Wideband Waveguide Transitions

A broadband terahertz amplifier waveguide module is presented. The IC chip with a width of 390
$\mu \text{m}$
fits in the
$E$
-plane of a standard WR-3.4 waveguide with 20
$\mu \text{m}$
air-gaps on either side. The input and output waveguide transitions integrated on the chip possess various design factors that include locations of the dipoles, back-short pedestal, and substrate vias carefully selected for near full-band characteristics. The measurements on a module containing a passive thru-line IC chip show only 2.7 dB of average loss across 220–300 GHz range. With an amplifier IC chip mounted inside, the module shows a peak gain of 17 dB at 288 GHz with a 3 dB bandwidth from 259 to 294 GHz.