[Script Info]
Title: 
[Events]
Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text
Dialogue: 0,0:00:00.00,0:00:02.97,Default,,0000,0000,0000,,>> All right, now let's\Ntalk about Power Splitter.
Dialogue: 0,0:00:02.97,0:00:05.56,Default,,0000,0000,0000,,The splitter is used to divide
Dialogue: 0,0:00:05.56,0:00:09.10,Default,,0000,0000,0000,,the signal that's on the line\Ninto two separate parts.
Dialogue: 0,0:00:09.10,0:00:11.84,Default,,0000,0000,0000,,The reason that we're going to\Ndivide it is because I need to know
Dialogue: 0,0:00:11.84,0:00:14.46,Default,,0000,0000,0000,,if it's 2.4 or 2.6 gigahertz.
Dialogue: 0,0:00:14.46,0:00:18.16,Default,,0000,0000,0000,,So it's going to go into to\Nband-pass filters in a minute.
Dialogue: 0,0:00:18.16,0:00:20.22,Default,,0000,0000,0000,,We call this thing a 3dB coupler,
Dialogue: 0,0:00:20.22,0:00:23.37,Default,,0000,0000,0000,,because 3dB means that it's\Ndividing the power in half,
Dialogue: 0,0:00:23.37,0:00:26.46,Default,,0000,0000,0000,,and a coupler is the same\Nas a splitter or a divider.
Dialogue: 0,0:00:26.46,0:00:29.19,Default,,0000,0000,0000,,So you can use this same\Ncircuit to either bring
Dialogue: 0,0:00:29.19,0:00:32.70,Default,,0000,0000,0000,,signals in like here and\Nhere and add them up,
Dialogue: 0,0:00:32.70,0:00:36.35,Default,,0000,0000,0000,,or to put them here and\Nsplit them down either side.
Dialogue: 0,0:00:36.35,0:00:40.79,Default,,0000,0000,0000,,So you could call it like\Na voltage divider in fact, in this case.
Dialogue: 0,0:00:40.79,0:00:42.30,Default,,0000,0000,0000,,So what we have right here is
Dialogue: 0,0:00:42.30,0:00:46.10,Default,,0000,0000,0000,,a 3dB coupler with\Na resistive element right here.
Dialogue: 0,0:00:46.10,0:00:49.40,Default,,0000,0000,0000,,What happens is in the event\Nthat I had things mismatched,
Dialogue: 0,0:00:49.40,0:00:51.67,Default,,0000,0000,0000,,or very unbalanced on either side,
Dialogue: 0,0:00:51.67,0:00:56.21,Default,,0000,0000,0000,,this resistor is going to absorb whatever\Namount of the signal is imbalanced.
Dialogue: 0,0:00:56.21,0:00:58.34,Default,,0000,0000,0000,,So the signal comes in right here,
Dialogue: 0,0:00:58.34,0:01:00.79,Default,,0000,0000,0000,,it splits down these two lines,
Dialogue: 0,0:01:00.79,0:01:03.02,Default,,0000,0000,0000,,and it goes into my band-pass filter.
Dialogue: 0,0:01:03.02,0:01:05.06,Default,,0000,0000,0000,,There's another cool thing\Nto note right here.
Dialogue: 0,0:01:05.06,0:01:07.84,Default,,0000,0000,0000,,See how these little quarters\Nhave been cut off?
Dialogue: 0,0:01:07.84,0:01:11.03,Default,,0000,0000,0000,,That's because a high-frequency quarters\Nradiate really well,
Dialogue: 0,0:01:11.03,0:01:13.99,Default,,0000,0000,0000,,and that's not generally something\Nthat you want in your circuit.
Dialogue: 0,0:01:13.99,0:01:16.30,Default,,0000,0000,0000,,Now, there's one form of 3dB coupler.
Dialogue: 0,0:01:16.30,0:01:18.82,Default,,0000,0000,0000,,Here is another form of 3dB coupler.
Dialogue: 0,0:01:18.82,0:01:20.60,Default,,0000,0000,0000,,What you can see right here is that we have
Dialogue: 0,0:01:20.60,0:01:24.98,Default,,0000,0000,0000,,a 50 Ohm line that goes\Ninto two 100 Ohm lines.
Dialogue: 0,0:01:24.98,0:01:27.09,Default,,0000,0000,0000,,That 200 Ohm lines are in parallel,
Dialogue: 0,0:01:27.09,0:01:29.54,Default,,0000,0000,0000,,so 100 in parallel with a 100 would be 50.
Dialogue: 0,0:01:29.54,0:01:33.28,Default,,0000,0000,0000,,So this is match 50 onto\Nthis set of 100s right here.
Dialogue: 0,0:01:33.28,0:01:34.97,Default,,0000,0000,0000,,Once you take microwave engineering,
Dialogue: 0,0:01:34.97,0:01:38.26,Default,,0000,0000,0000,,you're going to find out that these are\Nactually quarter wave transformers.
Dialogue: 0,0:01:38.26,0:01:41.34,Default,,0000,0000,0000,,This is a quarter of a wavelength\Nlong at 2.4 gigahertz.
Dialogue: 0,0:01:41.34,0:01:44.58,Default,,0000,0000,0000,,This is a quarter wavelength\Nlong at 2.6 gigahertz,
Dialogue: 0,0:01:44.58,0:01:47.98,Default,,0000,0000,0000,,and they're two quarter wave transformers\Ngoing down either side,
Dialogue: 0,0:01:47.98,0:01:50.40,Default,,0000,0000,0000,,that are perfectly\Nmatching this 50 Ohm line
Dialogue: 0,0:01:50.40,0:01:53.98,Default,,0000,0000,0000,,to the next set of\N50 Ohm lines on either side.