Intermodulation nulling in HEMT common source amplifiers

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

“…The power spectra of the IMD output components are illustrated Figure 3 at low frequency. When the input function of the amplifier is a signal with two tones: [6][7][8]…”

“…[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…”

“…The study of ref. 6,7, has investigated nonlinear behavior in transistors that included cross-terms, which is additional to the preceding trend described in ref. 5.…”

Effects of low-frequency drain termination and injection on nonlinear amplifier performances

“…To obtain a result that is easy to analyse, it is firstly assumed that the drain-to-source current is most critical to the nonlinear behaviour of the device, and secondly, that the drain-current variation ids can be expressed in terms of a limited Taylor series expansion. Although the validity of such a current model is limited to low signal variations, series expansion are generally applied to understand the intermodulation mechanisms as follows [11][12][13]:…”

Linearity analysis of SiGe HBT amplifiers using a power-dependent coefficient Volterra technique

“…Besides providing insights into the nonlinearity mechanism, Volterra series can handle memory elements typical in the high power amplifier [3]- [6]. To keep the analysis tractable and preserve its accuracy, Volterra series is often truncated to third-order to analyze weakly nonlinear RF amplifiers operating in class-A mode [4]- [5]. On the other hand, high efficiency CDMA power amplifiers typically operate in the class-AB mode and exhibit strong nonlinearities.…”