High-Output-Power and Reverse-Isolation G-Band Power Amplifier Module Based on 80-NM InP HEMT Technology

Using our in-house InP-HEMT technology, we have developed a PA module that operates in the G-band (140-220 GHz). The PA consists of 4-branch unit cells, each comprising six-stage medium power amplifiers. To obtain high gain and high linearity simultaneously, linear biasing technique for the unit cell of the PA was proposed. The fabricated PA MMIC is packaged in waveguide module using a ridge coupler as the transition between the MMIC and waveguide. A doped Si absorber on the ceiling of the module reduces leakage signal and achieves the high reverse isolation (inverted value of S
₁₂
). The fabricated PA module shows high gain (S
₂₁
) of over 22-dB at 140 - 190 GHz, high reverse isolation of over 45 dB at 140 - 200 GHz and high output power of over 13 dBm at 165 -185 GHz. It also shows high linearity, OP1dB of 8 dBm, at 169.5 GHz.