samchieh
Member level 1
I have a simple question.
I measured a 2 different pHEMT amplifiers from 2 separate companies. I used GSG probes for the input and output, and DC probes for biasing the drain and gate.
When I do this, the gain is signifantly lower than from the spec sheet.
When I add a external 1k series resistor between the DC supply and the DC probe at the gate, I get the advertised gain.
Why? Was I seeing oscillation? Is it because the gate needs current limiting?
I measured a 2 different pHEMT amplifiers from 2 separate companies. I used GSG probes for the input and output, and DC probes for biasing the drain and gate.
When I do this, the gain is signifantly lower than from the spec sheet.
When I add a external 1k series resistor between the DC supply and the DC probe at the gate, I get the advertised gain.
Why? Was I seeing oscillation? Is it because the gate needs current limiting?