Getting to the Heart of the Matter: Considerations for Large-Signal Modeling of Microwave Field-Effect Transistors

Performance projection of multi‐bias and nonlinear distortion for gallium arsenides nano‐pHEMT

“…When the input voltage exceeds the pinch‐off voltage V p , the device gains as the input voltage grows 14 . The parasitic effect in pHEMT devices then causes the gain in the second harmonic to start to decrease, resulting in the null 12–21 . As the channel length also affects the nonlinear behavior when the pinch‐off voltage profile changes with gate length (long gate lengths tend to have softer profiles) 1–11 .…”

“…In addition, the IMD3 component is often the most irritating because its frequency is close to the fundamental 11 . Even if it is not always possible to exclude the third‐order product, it can be reduced by running the amplifier with the second derivatives of the transconductance when g m3 is set to zero 12–19 . In addition, we presented a comprehensive mathematical framework for the components of the IMD at the output, which has been compared to data from the actual world measurements and found to be consistent in compliance.…”

“…devices then causes the gain in the second harmonic to start to decrease, resulting in the null. [12][13][14][15][16][17][18][19][20][21] As the channel length also affects the nonlinear behavior when the pinch-off voltage profile changes with gate length (long gate lengths tend to have softer profiles). [1][2][3][4][5][6][7][8][9][10][11] Before completing the two-tone intermodulation disorientation measurement, various…”

“…11 Even if it is not always possible to exclude the third-order product, it can be reduced by running the amplifier with the second derivatives of the transconductance when g m3 is set to zero. [12][13][14][15][16][17][18][19] In addition, we presented a comprehensive mathematical framework for the components of the IMD at the output, which has been compared to data from the actual world measurements and found to be consistent in compliance. Over a wide range of biasing, the IMD power elements at the output of transistors were found to obey how RF transconductance behaves and what results from its product.…”

120 GHz microstrip power amplifier MMICs in a commercial GaAs process

“…Our MQFET model [17] is fitted to the measured, extracted IV, and 50 GHz S-parameters over bias. Extracted correctly [18], the resulting model, when used with the single-finger approach, extrapolates to different device sizes and to the high frequencies used here. The model was checked for proper scaling with respect to transistor width and number of gate fingers with fresh S-parameter data measured to 110 GHz.…”