#1863
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26 күн бұрынEpisode 1963 chip of the day
Gallium Arsenide Transistor zoom zoom
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@jeffreypomeroy6173 23 күн бұрын
MESFETs are basically JFETs with a schottky junction instead of the pn/np junction at the gate.
@Peter-nf3wp 24 күн бұрын
I called P1dB 1 dB compression point back in the days i measured small amlifiers, and YES "chip of the day" is a favorite 👍
@deanbell5164 24 күн бұрын
I like the term 'happy place' for the bias :)
@jsdutky 24 күн бұрын
Aww. I was hoping for some time on the curve tracer.
@uploadJ 24 күн бұрын
For an RF device? As an end user of those devices we have never used a curve trace to look at an RF device, what we have used is manufacturer's 'test circuit' whose diagram and parts list (for impedance matching) is usually shown in the data sheet. Now, as a 'semiconductor fab' (manufacturer) of those devices, **we did** on-wafer testing doing pinch off (Vp), IDSS (zero V on gate and measure source to drain current), and gm (transconductance or DC gain) as these parameters indicate to the product engineers that the various fab steps **did** result in functional 'structures' comprising the device. On wafer DC tests also show which devices are candidates for subsequent mounting in a 'housing' for RF tests.
@AnalogDude_ 24 күн бұрын
HFA3046, HFA3096, HFA3127, HFA3128 from Renesas is the replacement for the well known CA3046, etc. capable of 8 gHz, not cheap either.
@hobbified 23 күн бұрын
PAE is just efficiency with the RF input (drive power) considered as a source of input power. Because with 10dB gain, Pin is equal to 10% of Pout, so just considering Pout / DCin would be ignoring a noticeable chunk of the power entering the amplifier.
@BalticLab 24 күн бұрын
Great video!
@wa4aos 24 күн бұрын
metal-semiconductor field-effect transistors (MESFETs)
@christopherleubner6633 24 күн бұрын
Ive seen some of these in cellular base stations, usually built into the antenna module block.
@byronwatkins2565 11 күн бұрын
Metal (ME) Semiconductor (S) FET. The metal-semiconductor junction forms a Schottky diode rather like the pn junction of JFETs.
@KeritechElectronics 24 күн бұрын
HF power transistors are definitely interesting!
@robinbrowne5419 24 күн бұрын
I wonder if you could remove the lid from one of the FETs and show us what is inside.
@winstonsmith478 24 күн бұрын
Using Octapart, Aztech (Italy) has 2,774 FLL120MKs in stock at $1.12 each at any quantity. Partstack confirms that with other high quantities in stock and cheap from other suppliers. If sold for the MUCH higher prices on that auction site, you could make a killing IF there was a significant demand which I seriously doubt seeing that there is only one FFL120 sale shown in a search for completed listings despite the large number of listings for that transistor.
@joseppuig925 24 күн бұрын
You can't trust the brokers, they may have fakes in their stock. They have a tendency to state that they have lots of units of the part you are searching for. I think they use a kind of automated script to report back the search query with some random number to octopart, and when you buy it, they "prepare" the ICs for you.
@TranscendentBen 24 күн бұрын
4:27 Yeah, that looks a LOT like vacuum tube characteristic curves with negative grid bias! The voltage and current scales do look a little off, though.
@sundog486 24 күн бұрын
Yes. I explain vacuum tubes to young whippersnappers by saying they behaved like depletion mode FETs. Then they ask what is depletion mode?
@ChrisJackson-js8rd 24 күн бұрын
would that serial number be from the manufacturer or from the seller?
@alistairmackintosh9412 24 күн бұрын
No frequency response curve?
@richysradioroom 24 күн бұрын
nice
@geirha75 21 күн бұрын
40% efficient? So like 60% of the input power is dissipated as heat?
@Dr_Mario2007 23 күн бұрын
Kinda funny that it wouldn't be long before computer chips use basically the same stuff as RF transistors (for good reasons as they tend to grip on electrons better than Silicon counterpart especially when transistors get much smaller). Still, HEMTs (high electron motility transistors) are an interesting technology as whole.
@SimEon-jt3sr 13 күн бұрын
Why tho can't they just somehow analog and just have crazy gigahertz radio type stuff. Idk how it works. But that's probably the future right? Kind of a blend. Of everything
@TheRcEngineer 21 күн бұрын
This might make a good qo100 amp 2.4 Ghz is out of L Band but the datasheet specs at 2.3 Ghz
@Clancydaenlightened 24 күн бұрын
Use it to make a 1 or 2 ghz drsstc But the secondary would have to resonate at a harmonic several wavelengths longer Unless you want 2 or 3 inch secondary
@Clancydaenlightened 24 күн бұрын
I don't think that's class E anymore
@Clancydaenlightened 24 күн бұрын
Damn now running a Tesla coil will knock out wifi and phone service within a few miles At that resonant frequency
@DiaconescuAlexandru2024 24 күн бұрын
And I thought buying IRF510's for my DIY RF amp was getting expensive!
@richysradioroom 24 күн бұрын
$1.50?? LOL
@BeesKneesBenjamin 24 күн бұрын
IRF510 for an RF amplifier?? Are you building an end stage for an LW radio transmitter? I've used them for designing switching powersupplies! :-)
@uploadJ 24 күн бұрын
@@BeesKneesBenjamin Believe it or not, the IRF510 can be coerced into operation up to 30 MHz, Now, is it ideal - well, it is cheap so it has that going for it. Do a little searching, there are even vids on the design of HF amps using that device.
@DiaconescuAlexandru2024 19 күн бұрын
@@richysradioroom Average salary here in Romania is $400, just the IRF510's were $5 but I also have to buy the other components :)
@DiaconescuAlexandru2024 19 күн бұрын
@@BeesKneesBenjamin 50W amp for the 10 meter band, for SMPS's I have MJE13005's and DK112's
@davidsmith9063 24 күн бұрын
You are SO SO So VERY lucky to have gotten that amp for that price, destroyed or not! That's the kind of thing i can never find for that $$$. Enjoy all of those devices!! I'm absolutely GREEN! 🤓 Thank you for another useful video. have fun with those!!!! - KE5DEV
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