From 6 to 10 GHz, the pole lies inside the Γ 3 = 1 boundary of the Smith Chart in Figure 4.10, indicating that negative resistance can be generated in this device using passive shunt feedback. An example of the use of a compressed Smith Chart to plot the negative resistance behavior of an MHG9000 GaAs MESFET, in terms of shunt feedback pole locations (as defined in Chapter 8) on the Γ 3 plane from 2 to 18 GHz is shown in Figure 4.10. In order to represent negative resistances we need to compress the conventional Smith Chart to be a subset of a larger chart, which typically has a radius of |Γ| = 3.16, this value being chosen to represent 10 dB return gain. Negative resistance values plotted on a Smith Chart lie outside the |Γ| = 1 boundary of the conventional Smith Chart.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |