triple_core
Member level 3
pa stability
Hi everyone,
I'm a beginner in PA design. In the interstage matching, I use simple high pass to transfer the impedance. After tunning, I find the performance of my PA can be much better. But the output of the interstage matching is higher than the input. I think the output must smaller than the input so I made the stability simulation. I find if I put a serial resistor to the base of third stage HBT, the stability factor is larger than 1. But why the output is larger than the input?
In the following is the waveform of the output of second stage and input of the third stage. Does it oscillate or not? Thanks.
Hi everyone,
I'm a beginner in PA design. In the interstage matching, I use simple high pass to transfer the impedance. After tunning, I find the performance of my PA can be much better. But the output of the interstage matching is higher than the input. I think the output must smaller than the input so I made the stability simulation. I find if I put a serial resistor to the base of third stage HBT, the stability factor is larger than 1. But why the output is larger than the input?
In the following is the waveform of the output of second stage and input of the third stage. Does it oscillate or not? Thanks.