Johnson figure of merit

Johnson figure of merit (high-power applications) 1 7 16 1138... 

The Johnson figure of merit (JFM) is used to compare materials for power microwave applications. Larger values indicate superior performance in microwave power applications. The higher the value, the higher will be the power capability. This figure of merit is the product of the breakdown voltage (Vb) and the electron saturation velocity (Ljat). 

Table 2 Johnson figure of merit (JFM) of some wide band-gap semiconductors...

DECAMP asked for a more quantitative idea of the accuracy of phasing and of the necessary precision in the measurements of the structure amplitudes. JENSEN said the figure of merit is the cosine of the error in phase angle so that if the figure of merit is, for example, 0.7, the angular error is about 45°. To find out the reliability of structure amplitudes, one can measure different crystals and symmetry-related reflections. JOHNSON mentioned Schoenbom s numerical results where, using either unit or correct amplitudes and the correct phases from a model, it is possible to see the molecule. 

The device potential of a semiconductor material is often estimated in terms of figures of merit. The Johnson s and Keyes figures of merit are frequently used. Johnson s Figure of Merit (JFM) addresses the potential of a material for high-frequency and high-power applications [8] ... 

FIGURE 1 Figures of merit for Si, GaAs and SiC. KFM - Keyes figure of merit, JFM - Johnson s figure... 

JFET JFM junction field effect transistor Johnson s figure of merit... 

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