Video 5.3 - Conquer Radio Frequency

This video employs a BFP405 transistor model which was readily available in AWR v11. If you can't find this model in newer versions, please download this simulation file which includes the BFP405 model explorerf.com/BFP405_from_AWR_...
Content:
Amplifier Stability Part 1.
Gain Variation versus frequency. Polar representation of S21. Explanation of how the phase winds back as frequency increases thereby making input-output interaction more likely and increasing risk of oscillations.
Rationale behind stabilisation: attempt to conjugate match input without stabilising and demonstration of resulting output instability.
Mu factor: a single parameter as an indicator of potential instability and unconditional stability.Input and output stability circles.
Resistive stabilisation with shunt and series resistors at input and/or output and its limitations.
Version 13 update: In version 13, “To” and “From” ports must now be specified for a number of two-port measurements. This was not required for version 12 or earlier. The measurement “MU1()” shown in the video has now been replaced by MU1(2,1) in version 13. That is "To port"=2, "From port"=1. "MU2()" has also been replaced by MU2(2,1). The measurement “SCIR1()” shown in the video has now been replaced by SCIR1(2,1) in version 13. “SCIR2()” has also been replaced by SCIR2(2,1).
You may download the "Conquer Radio Frequency" e-book, which provides support material for these videos, at explorerf.ipage.com/conquer_ra...
Intro: (0:00)
S21 versus Frequency: (3:08)
Matching input impedance of transistor and instability: (6:50)
Mu Factor and instability: (14:40)
Stability circles: (18:45)
Input stabilisation with series resistance: (27:00)
Output stabilisation with series seristance: (31:00)
Output stabilisation with shunt resistance: (33:10)

[@akosbuzogany2752]

Awesome! A lesson worth thousands of $$$

[@ExploreRF]

Glad you liked it!

[@soroushmoallemi774]

I honestly don't know how to thank you for this amazing, amazing video. Perfect job

[@ExploreRF]

I am really pleased that you found it useful

[@mahruzaziz6790]

Very good explanation for Stability topic. Thanks a lot

[@ExploreRF]

Thanks!