WEBVTT

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>> All right, now let's
talk about Power Splitter.

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The splitter is used to divide

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the signal that's on the line
into two separate parts.

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The reason that we're going to
divide it is because I need to know

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if it's 2.4 or 2.6 gigahertz.

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So it's going to go into to
band-pass filters in a minute.

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We call this thing a 3dB coupler,

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because 3dB means that it's
dividing the power in half,

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and a coupler is the same
as a splitter or a divider.

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So you can use this same
circuit to either bring

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signals in like here and
here and add them up,

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or to put them here and
split them down either side.

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So you could call it like
a voltage divider in fact, in this case.

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So what we have right here is

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a 3dB coupler with
a resistive element right here.

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What happens is in the event
that I had things mismatched,

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or very unbalanced on either side,

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this resistor is going to absorb whatever
amount of the signal is imbalanced.

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So the signal comes in right here,

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it splits down these two lines,

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and it goes into my band-pass filter.

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There's another cool thing
to note right here.

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See how these little quarters
have been cut off?

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That's because a high-frequency quarters
radiate really well,

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and that's not generally something
that you want in your circuit.

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Now, there's one form of 3dB coupler.

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Here is another form of 3dB coupler.

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What you can see right here is that we have

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a 50 Ohm line that goes
into two 100 Ohm lines.

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That 200 Ohm lines are in parallel,

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so 100 in parallel with a 100 would be 50.

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So this is match 50 onto
this set of 100s right here.

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Once you take microwave engineering,

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you're going to find out that these are
actually quarter wave transformers.

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This is a quarter of a wavelength
long at 2.4 gigahertz.

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This is a quarter wavelength
long at 2.6 gigahertz,

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and they're two quarter wave transformers
going down either side,

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that are perfectly
matching this 50 Ohm line

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to the next set of
50 Ohm lines on either side.