At a trade show, Tek demo'd a little box that accepted SD-series sampling heads and had a computer interface, but they never offered it for sale.
The heads are cheapish on ebay, so someone could make such a box.
The SD heads are really good,
I want to inject a fast pulse, 1 volt or so, into a transmission line.
25 ohm source, 25 ohm load.And I want to really disconnect when we're not injecting this pulse.
A 0.25 pF schottky would have its diode drop and an extra 10 ohms of series resistance. The PIN is just 2 ohms.
What? The PIN has its diode drop too. The 2 ohms is the dynamic resistance.
Jeroen Belleman
"Impedance" please, John Larkin went to Tulane, so he probably doesn't know better, but you should. It is mostly capacitative.
The John Doe troll stated the following in message-id <sdhn7c$pkp$ snipped-for-privacy@dont-email.me:
And the John Doe troll stated the following in message-id <sg3kr7$qt5$ snipped-for-privacy@dont-email.me:
And yet, the clueless John Doe troll has itself posted yet another incorrectly formatted USENET posting on Fri, 22 Oct 2021 03:40:47 -0000 (UTC) in message-id <sktbrv$trh$ snipped-for-privacy@dont-email.me.
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The John Doe troll stated the following in message-id <sdhn7c$pkp$ snipped-for-privacy@dont-email.me:
And the John Doe troll stated the following in message-id <sg3kr7$qt5$ snipped-for-privacy@dont-email.me:
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PINs are ohmic for fast signals. That's the point.
Where are you able to find any MADP-008120-12790T parts in stock ??
boB
Here is a paper that describes a pulse generator using step recovery diodes:
Digikey and Richardson show "factory stock."
OK, it says they do ! I looked through OEMs Trade or Octopart and showed zero.
But going to Digikey separately showed what you said.
Wonder if there is any difference in "factory stock" and regular stock ?
On a sunny day (Fri, 22 Oct 2021 17:06:58 -0700 (PDT)) it happened Flyguy snipped-for-privacy@yahoo.com wrote in snipped-for-privacy@googlegroups.com:
Nice, thanks.
Yeah, I don't really understand why John can't bias a diode--he seems so competent otherwise. lol
PIN switch diode bias networks can create spikes on the signal lines at transition because of the energy stored in the bias chokes. In many apps that does not matter because the signal is not "looked at" during transition. In spook monitors/equipment, that spike is not allowed to go out to antennas.
I almost had a need for a switch with something like a 105 dBm SHI rating a while back. I was looking at Metelics PINs (Macom has Metelics now). GaN did not cut it at all. We got off to other things--it never came to fruition.
Robert H. Caverly is "the guy" for PIN diodes. He wrote a lot of papers.
Caverly and Quinn: A SPICE MODEL FOR SIMULATING THE IMPEDANCE-FREQUENCY CHARACTERISTICS OF HIGH FREQUENCY PIN SWITCHING DIODES ^ disclaimer: I have not personally used this or looked into it at all.
Microsemi used to have THE PIN DIODE CIRCUIT DESIGNERS’ HANDBOOK. I did not look for it.
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