Fast pulse rise/fall of 290 ps - Page 1
Forum section: electronics / testgear

author: eurofox
author_rank: Unknown
timestamp: March 28, 2014, 03:10:34 pm
content: From Time Mark Generator

author: Carrington
author_rank: Super Contributor
timestamp: March 28, 2014, 03:50:47 pm
content: And what did you expect?Or just want to brag about?

author: EV
author_rank: Frequent Contributor
timestamp: March 28, 2014, 04:10:57 pm
content: You can not measure rise time with sine wave, you must use square wave.

author: Carrington
author_rank: Super Contributor
timestamp: March 28, 2014, 04:32:58 pm
content: Quote from: EV on March 28, 2014, 04:10:57 pmYes, it would be the right waybut it is close to the limit: 333ps x 80% -> 266ps vs 290psI'm sorry, I don't know where I got 333ps.

author: eurofox
author_rank: Unknown
timestamp: March 28, 2014, 04:47:14 pm
content: Quote from: Carrington on March 28, 2014, 03:50:47 pmThe is the only fast output on this instrument, no square option.My only intention was to show that this is "faster" than the different avalanche and other already posted.eurofox

author: BravoV
author_rank: Super Contributor
timestamp: March 28, 2014, 04:50:26 pm
content: Quote from: eurofox on March 28, 2014, 04:47:14 pmNot mine, but try to beat this (Alan's toy):

author: Carrington
author_rank: Super Contributor
timestamp: March 28, 2014, 04:56:37 pm
content: Quote from: eurofox on March 28, 2014, 04:47:14 pmI understand, but you should use a square pulse.For 1GHz sinusoidal -> 500ps x 80% = 400ps (is only a rough estimation, valid for a ramp) vs ~ 300ps.So 330ps (10 to 90% for 1GHz sinusoidal) may be closer to reality.This only happens when one speaks without thinking, at the end I screw up.

author: Lukas
author_rank: Frequent Contributor
timestamp: March 28, 2014, 05:02:19 pm
content: Quote from: BravoV on March 28, 2014, 04:50:26 pmEasy job with an NBSG11:(https://www.mikrocontroller.net/topic/295617#3335040) Though amplitude is limited to 400mVpp

author: BravoV
author_rank: Super Contributor
timestamp: March 28, 2014, 05:08:02 pm
content: Quote from: Lukas on March 28, 2014, 05:02:19 pm400mVpp ... meh ... click the link I provided, that signal was measured using a 20dB attenuator, just calculate yourself the signal rise time or volt/second.

author: Lukas
author_rank: Frequent Contributor
timestamp: March 28, 2014, 05:34:06 pm
content: Quote from: BravoV on March 28, 2014, 05:08:02 pmIf I'm right a fast risetime is more relevant for bandwidth evaluation than a steep slope. Has someone tried connection a diode across the output of an avalanche pulse generator to convert it's steep slope into a fast risetime?

author: EV
author_rank: Frequent Contributor
timestamp: March 28, 2014, 06:15:50 pm
content: Quote from: BravoV on March 28, 2014, 04:50:26 pmWhat about this?

author: Carrington
author_rank: Super Contributor
timestamp: March 28, 2014, 06:22:49 pm
content: Welll, after doing a simulation, for 1GHz sinusoidal tr (10 to 90%) is 300ps:

author: EV
author_rank: Frequent Contributor
timestamp: March 28, 2014, 06:24:04 pm
content: Quote from: Lukas on March 28, 2014, 05:02:19 pmThis does not look rise time between 10% - 90% from max amplitude.

author: Lukas
author_rank: Frequent Contributor
timestamp: March 28, 2014, 06:34:05 pm
content: Quote from: EV on March 28, 2014, 06:24:04 pmIt's 20-80

author: EV
author_rank: Frequent Contributor
timestamp: March 28, 2014, 06:56:18 pm
content: Quote from: Lukas on March 28, 2014, 06:34:05 pmRt10-90 = Ln(9) / Ln (4) x Rt20-80 = 1.58 x 49 ps = 77 ps.

author: krenzo
author_rank: Regular Contributor
timestamp: March 29, 2014, 05:45:46 am
content: My condolences to all of you slow pokes (minus EV).

author: EV
author_rank: Frequent Contributor
timestamp: March 29, 2014, 06:41:22 am
content: Quote from: krenzo on March 29, 2014, 05:45:46 amCongratulations! You have nice clean pulse.

author: eurofox
author_rank: Unknown
timestamp: March 29, 2014, 09:35:00 am
content: Quote from: krenzo on March 29, 2014, 05:45:46 amI have a plan to build a fast rise pulse generator with a comparator, I have all the components since 6 months, only the time is missing.The 290ps pulse come from a normal instrument and not a custom build super fast pulse generator.It is nice and interesting to generate reaction here, only is missing with the pulse images the circuit that generate it.eurofox

author: EV
author_rank: Frequent Contributor
timestamp: March 29, 2014, 10:16:56 am
content: Quote from: eurofox on March 29, 2014, 09:35:00 amMy pulse is from Tektronix pulse generator type 284. The scope is Tektronix R7103 with 7T11 and 7S11 plugins and S-4 sampling head.

author: krenzo
author_rank: Regular Contributor
timestamp: March 29, 2014, 03:07:36 pm
content: Mine is from aTektronix SD-24 TDRthat I just got a few weeks ago. I also have a comparator based pulse generator circuit that I built myself, but it can only do 70ps of rise time.

author: Carrington
author_rank: Super Contributor
timestamp: March 29, 2014, 04:31:47 pm
content: This pulse generator achieve a tr of 60ps.https://www.eevblog.com/forum/projects/transmission-line-avalanche-pulse-generator/msg358382/#msg358382I would like to get one like that, not very expensive.Can you recommend one? Something like this (is a 35 ps rise time edge generator based on a ONET8501):https://www.kickstarter.com/projects/1855991221/10-ghz-usb-oscilloscopeThanks.

author: krenzo
author_rank: Regular Contributor
timestamp: March 30, 2014, 01:42:28 am
content: Can you not build your own? It's not that difficult if you're just using the ONET8501.

author: Carrington
author_rank: Super Contributor
timestamp: March 30, 2014, 02:00:06 am
content: Quote from: krenzo on March 30, 2014, 01:42:28 amSure, but probably someone already did, so I could save time and maybe some money.

author: Hugoneus
author_rank: Frequent Contributor
timestamp: March 30, 2014, 03:49:52 am
content: One of my publications from 2008!The circuit has a sub 6ps rise time.Now days this number is obsolete. Although, this may still be the fastest CMOS retimer reported to date.

author: eurofox
author_rank: Unknown
timestamp: March 30, 2014, 09:10:11 am
content: Quote from: Hugoneus on March 30, 2014, 03:49:52 amPlease post schematic and information.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: March 30, 2014, 09:31:32 am
content: Won't do you much good, it's probably monolithic on InP.Tim

author: eurofox
author_rank: Unknown
timestamp: March 30, 2014, 10:00:13 am
content: Quote from: T3sl4co1l on March 30, 2014, 09:31:32 amI'm sure about it, because with "normal" components we can expect maximum +/- 30ps.

author: Hugoneus
author_rank: Frequent Contributor
timestamp: March 30, 2014, 02:22:11 pm
content: Quote from: eurofox on March 30, 2014, 10:00:13 amIt is monolithic, but not InP. It was implemented in 65nm CMOS GP process from ST. You can find the publication online:Shahramian, S.; Carusone, A.C.; Schvan, P.; Voinigescu, S.P., "An 81Gb/s, 1.2V TIALA-Retimer in Standard 65nm CMOS," Compound Semiconductor Integrated Circuits Symposium, 2008. CSIC '08. IEEE , vol., no., pp.1,4, 12-15 Oct. 2008

author: Carrington
author_rank: Super Contributor
timestamp: March 30, 2014, 03:04:55 pm
content: I found this:https://tspace.library.utoronto.ca/handle/1807/30039(pag. 77, pfd)and this:http://www.eecg.utoronto.ca/~tcc/SHAHRAMIAN_CSICS_2008_SlidesFINAL.pdfCool!

author: Neganur
author_rank: Unknown
timestamp: March 30, 2014, 03:08:57 pm
content: I think time mark generators serve a different purpose than rise time verification/adjustment.

author: han
author_rank: Frequent Contributor
timestamp: March 30, 2014, 03:18:32 pm
content: Is it possible some day RF and Optic technology meet?since 110 GHz Mixer is available and 300GHz is already in Infrared zone(Infrared 700 nm – 1 mm 430 THz – 300 GHz)

author: Nerull
author_rank: Frequent Contributor
timestamp: March 30, 2014, 03:22:23 pm
content: Detectors for far-IR have to operate near absolute zero, because everything emits IR - optics, sensors, fiber cables, enclosures, etc. Any signal is lost in the flood of IR coming from the equipment itself. Test equipment with a built in helium-3 cooling loop - I wonder how much that would cost.

author: Hugoneus
author_rank: Frequent Contributor
timestamp: March 30, 2014, 03:29:52 pm
content: Quote from: Carrington on March 30, 2014, 03:04:55 pmThanks!Brings back memories.

author: Hugoneus
author_rank: Frequent Contributor
timestamp: March 30, 2014, 03:35:08 pm
content: Quote from: han on March 30, 2014, 03:18:32 pmWell, making a very simple 300GHz generator is not that difficult. I can make you a multiplier or a fourth harmonic VCO to put out a little power at 300GHz which then you can collect with a 300GHz probe with a waveguide interface. But propagating 300GHz is not so simple. Copper 'wire' simply does not support transmission at such frequencies because it would be lossy. You cannot move electrons back and forth in Copper at that rate.Waveguide is of course different. After all, fiber optics are waveguides.

author: han
author_rank: Frequent Contributor
timestamp: March 30, 2014, 03:42:36 pm
content: Quote from: Hugoneus on March 30, 2014, 03:35:08 pmJust curious ,is there any PMD/CD effect(similiar) in high frequency wave guide?

author: Hugoneus
author_rank: Frequent Contributor
timestamp: March 30, 2014, 04:06:12 pm
content: Quote from: han on March 30, 2014, 03:42:36 pmThe medium in waveguide is air (with metallic walls of course). You are dealing with mostly losses. If you keep extending the required bandwidth (say you want to occupy 50GHz around 300GHz), you will run into bandwidth limitations. So in a sense, you would have similar issues, but we don't call them PMD/CD.

author: eurofox
author_rank: Unknown
timestamp: March 30, 2014, 04:47:18 pm
content: Quote from: Neganur on March 30, 2014, 03:08:57 pmI agree but there is an output on this instrument with rising edge of 5ns, 2ns and a special output for 1ns, they all are faster than indicated.eurofox