Extremely high frequency amplifier self-excited how to adjust?

Extremely high frequency amplifier self-excited how to adjust?
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Working band in the 18-31 GHZ, is a amplifier components, with two of the internal active radio frequency amplifier chip, the input power 0 dBm, output power + 30 dBm. The output signal has self-excited phenomenon, how to eliminate the phenomenon of self-excited, rf power supply voltage of the chip is not pure the influence of self-excited? Alphabetical order.
The power supply voltage instability will easy to cause the self-excited,
18-31 GHZ frequency, really tall, my experience I say little bit.
A, circuit design should be very hard, your chip power pin must use filter capacitance, your circuit before a current should not amplified, the proposal USES 220 UF and 0.1 UF capacitance parallel access, to ripple suppression effect is good. And go short circuit line as far as possible, so high frequency, must use shielding measures, preferably by shielding the circuit box up and grounded. Or as we usually radio signals, and cell phone signals, etc, all kinds of interference will be induced to circuit. Then you want to self-excited is too simple.
Second, power supply must be very stable, power supply voltage, had better use high precision oscilloscope see wave ?