jianke
Member level 3
Recently I met an interesting question for RF amplifier design. As we know, by adding a series inductor at Emitter, we can increase the stability of a BJT Common-Emitter (CE) amplifier. When it comes to a Common-Base (CB) or a Common-Collector (CC) amplifier, what should we do to increase its stability?
My objective is at 2.14GHz: (1) the CB amplifier works as a “current follower” (voltage amplification); (2) the CC amplifier works as a “voltage follower” (current amplification).
What I have tried for a CB amplifier is:
(1) Adding a series resistor at output, but the S parameters becomes really bad, typically S11 and S22. Also, the voltage gain decreases much.
(2) Using the ADS optimization tool to improve stability and S-parameters performance, but the results are not good. Typically the CB amplifier cannot work as a “current follower”. Also, the voltage gain decreases much.
The attachments are ADS simulations files and some simulations results. I hope they would be useful for your analysis. Thanks!
My objective is at 2.14GHz: (1) the CB amplifier works as a “current follower” (voltage amplification); (2) the CC amplifier works as a “voltage follower” (current amplification).
What I have tried for a CB amplifier is:
(1) Adding a series resistor at output, but the S parameters becomes really bad, typically S11 and S22. Also, the voltage gain decreases much.
(2) Using the ADS optimization tool to improve stability and S-parameters performance, but the results are not good. Typically the CB amplifier cannot work as a “current follower”. Also, the voltage gain decreases much.
The attachments are ADS simulations files and some simulations results. I hope they would be useful for your analysis. Thanks!
Attachments
-
Simulation Results for CB Configuration.pdf208.1 KB · Views: 99
-
BFP740ESD Readme_Spice_for_ADS_MWO.pdf74.8 KB · Views: 77
-
BFP740ESD_spar10GHz_noisepar10GHz_spice10GHz_ADS_MWO.zip180.8 KB · Views: 78
-
BFP740ESD(ft45GHz)_DataSheet.pdf2.1 MB · Views: 66
-
ADS Simulation Files (CB & CC).rar19.6 KB · Views: 72
Last edited: