Benchmarking a High Electron Mobility Transistor Using an Active Load-Pull System at 120 GHz–170 GHz

This study presents an in-depth investigation into the high-frequency capabilities of a commercial 100 nm InP high electron mobility transistor (HEMT) through small and large signal analysis. The report centres on the analysis of output power, gain, and power-added efficiency (PAE), aiming to provide an accurate and comprehensive evaluation of device performance. Initially, the DC characteristics of the test transistor are examined to ascertain the optimal operating point. The large-signal performance is conducted in non-50 Ω impedance conditions, employing active load-pull measurements up to 170 GHz. The obtained measurement results reveal that the transistor achieves a gain surpassing 0.5 dB at 170 GHz in a 50 Ω S-parameter measurement system, however, the subsequent non-50 Ω measurements show a PAE of 6.5 % and a gain of 3.5 dB at 170 GHz. These values are in good agreement with numerical modelling results. These findings have revealed the true potential of these devices.