Transistor Impedance Matching

Gregory explains impedance matching of a transistor, showing the impedance transformation on the Smith Chart.

The Smith Chart is explained and used to help the design of an LC impedance match network, to match the input impedance of a BJT transistor.

Video showing what is impedance matching:

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00:20 - General impedance matching
02:20 - Why impedance match a transistor
05:02 - Transistor input impedance
06:50 - The Smith Chart
09:50 - Impedance Match Network design

[はいこれはロボ子の婚約者]

i wish i had the same enthusiasm for life as this guy has for impedance matching

[iwbnwif]

I have seen similar demonstration of Smith chart impedance matching many times, but this is by far, far, far the clearest and most engaging presentation ever!! You're a genius :) The only thing missing was a P vs Rload graph at the start to show why max. power requires matched load, but I'm sure most people know that anyway.

[TekCroach]

In case of the transistor, the maximum power transfer law doesn’t apply. Usually we deal with signal voltage here. Therefore we try to extract (or drop across the transistor input port) the highest possible voltage. We should consider it as a voltage divider circuit. So, the transistor’s input impedance should be as high as possible. We don’t match impedances there.

[RyanBoggs]

Great content as usual! Just one question. Is ~36 ohms a typical small signal base-emitter resistance for a BJT in RF applications? Ive not yet seen one that small. Seems that would roughly equate to a base DC bias current of about 720 uA and that seems pretty high compared to what Im used to designing.

[VictorFerreiraBMX]

Saudades dos seus vídeos em português, quando eu consegui juntar dinheiro para comprar os seus cursos, vi que não existe mais, vídeos bloqueados... que pena, você me foi um dos motivos para iniciar engenharia elétrica... abraço.. agora vai ser um motivo para aprender inglês kkk

[umpoucosobreconhecimentos]

The most clearest explanation about smith chart that I ever seen. Congratulations

[steniomedeiros]

Fantastic video! Really great work! This model of representation and modeling takes us to another level. Leading us to imagine even in materials engineering concepts.

[sersheva]

Excellent video Gregory, I have seen many of matching impedance circuit at one specific frequency but how can I design a broadband matching impedance for example for TV signal of 6MHz bandwidth

[therfnoob]

great video!!! Amazing informations! i'd love to know what technique you used to measure the input impedance of your transistor. Also, could you discuss how to measure the output impedance of the transistor?

[plazmaguyyago]

i am currently going through the art of electronucs and the first 2 minutes of this video makes so much sense now there is an exrecise in the book that calls for proving that the maximum power supplied by a non ideal voltage source to a load is when r=R (internal = load)

[mr.cunamis]

Hi gregory. Good video. Are there any networks methods that allows matching on multiple aribitrary wide- bands and not just a single frequency?

[luisilichvladimirguerrerol]

I am not an expert in this topic, but could you explain what happenen if the input impedance is infinite. Is the power delivered zero?

[WRMD]

Great tutorial! You really make this concept much easier to understand. (Sorry to be the 778th like ruining the lucky 777 likes.)

[khimbittle]

very good video, look forward to a video describing how to determine transistor base impedance

[franciscoferreira-ehyu]

dude, I was happy working with pure dc, making some power supplies, why I clicked here ?

[mohammedzakariawakil]

Please engr my problem is how do I know the input and output impedance of transistors or I will used transistor datasheet thanks

[aronhighgrove]

Good content, but please less intense/less coffee haha, it's stressing and the "shouting" makes it hard to focus.

[yakovdavidovich]

Wow, once again you present something I've read about, and struggled with, and with one simple comment you bring it all into clarity. I don't think I've found anyone who explained that the cartesian plot is transformed into the circular form of the smith chart. I've just seen the Smith chart presented as-is. Now, as I watch the video, I imagine how the transformations look back on the cartesian view, and everything is making sense!

[ronpearson]

Absolutely incredible - this is my first patron channel - I struggled with smith charts in my EE program

[stephenamy]

sorry to many jump cuts, and repetitions. made it hard to follow