ADS Software model of SD57060 shows that the device is unstable at 945MHz. To get stability factor greater than one over the desired band , i add 3 ohm resistor at the gate side. After stabilizing it load pull test shows that maximum power can not be achieved using 3 watt input power as shown in the device datasheet. Why datasheet shows maximum power without stabilizing the device
Well, since the input impedance of that device is 0.7 ohms, adding a 3 ohm series resistor at the gate will have a very big impact! Try stabilizing it using some other method. The data sheet shows a recommended circuit layout.
Simulation of sd57060 exactly with the layout given in the datasheet Shows k>1 .
ADS shows the following warning. even at low drive power 25dbm
Simulation / Synthesis Messages
Warning detected by hpeesofsim during HB analysis `HB1'.
Circuit converged with at least one device's P-N junction current
exceeding the explosion current and junction has been linearized.
You may want to increase the explosion current in the device model or in
the Options (if the parameter is not given in the model) and resimulate.
You may need to increase Maximum number of warnings under Output tab
in Options to see which devices have been linearized.
Warning detected by hpeesofsim during HB analysis `HB1'.
Diode `X1.DIODE1' explosion current exceeded.
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what is the configuration for RLC at gate to source?
Is it possible to stabilize amplifier by fixing only input and output matching networks? I noticed that during the adjustment of input and output matching networks, the ADS SIMULATION shows that SD57060 becomes marginally stable over certain bandwidth.