A comparison of the measured to modelled small-signal performance is plotted in Figure 4. The measured results are the dotted traces and the modelled (simulated) performance is the solid traces. It can be seen that there is a slight shift upwards in frequency of the measured performance compared to the modelled, but the agreement is good.
The large signal performance was also measured RF-on-Wafer (RFOW). This was measured under pulsed operation at a duty cycle of 10% with a pulse width of 25µs. The measured results are plotted in Figure 5(a) for RF input powers of 5 dBm, 19 dBm, 29 dBm and 32 dBm at a quiescent bias of 25V, 90mA. With an input power of 29 dBm the RF output power is around 38.5 dBm or 7W.
A corresponding plot of the PAE (Power Added Efficiency) is shown in Figure 5(b). At an input drive of 29 dBm the PAE is around 42% from 9 to 11.5 GHz.