power amplifier design problem. call for help.
时间：04-09
整理：3721RD
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Hi, everyone,
In my power amplifier design, When I place 4 transistors in parallel as output stage, it can delivery 24 dBm power.
When add more transistors in parallel (base current increased accordingly), the output power doesn't increase but decrease to 23 dBm. Why? should I need do a input matching network before the transistors ?
Is there anybody can show me the reason?
Thanks.
The simulation is performed in ADS.
In my power amplifier design, When I place 4 transistors in parallel as output stage, it can delivery 24 dBm power.
When add more transistors in parallel (base current increased accordingly), the output power doesn't increase but decrease to 23 dBm. Why? should I need do a input matching network before the transistors ?
Is there anybody can show me the reason?
Thanks.
The simulation is performed in ADS.
sure u will need new output matching circuit , coz as u make new paralle transistors the output impedance of the all netweok wil be decreased , so u need new matching circuit to match the new impedance
khouly