Isola microwave laminate...

[John Larkin]

I only needed 3 square inches, but they sampled me a full panel. Good,
I\'ll have some around for fast protos.

https://www.dropbox.com/sh/fva424mq477k857/AACy1-4WS7yddHNOKpeg3w4Fa?dl=0

This is much better than FR4, and the board houses say it handles like
FR4.

 

[Phil Hobbs]

On 2020-10-22 17:13, John Larkin wrote:

I only needed 3 square inches, but they sampled me a full panel. Good,
I\'ll have some around for fast protos.

https://www.dropbox.com/sh/fva424mq477k857/AACy1-4WS7yddHNOKpeg3w4Fa?dl=0

This is much better than FR4, and the board houses say it handles like
FR4.


That is a lot better.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com

 

[John Larkin]

On Thu, 22 Oct 2020 17:51:10 -0400, Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:

On 2020-10-22 17:13, John Larkin wrote:


I only needed 3 square inches, but they sampled me a full panel. Good,
I\'ll have some around for fast protos.

https://www.dropbox.com/sh/fva424mq477k857/AACy1-4WS7yddHNOKpeg3w4Fa?dl=0

This is much better than FR4, and the board houses say it handles like
FR4.


That is a lot better.

Cheers

Phil Hobbs

Nice crisp step, no ugly drool.

I\'ll try a 4-layer board for real. My SFP link thing is really
suffering from the FR4 losses.

 

[Phil Hobbs]

On 2020-10-22 18:09, John Larkin wrote:

On Thu, 22 Oct 2020 17:51:10 -0400, Phil Hobbs
pcdhSpamMeSenseless@electrooptical.net> wrote:

On 2020-10-22 17:13, John Larkin wrote:


I only needed 3 square inches, but they sampled me a full panel. Good,
I\'ll have some around for fast protos.

https://www.dropbox.com/sh/fva424mq477k857/AACy1-4WS7yddHNOKpeg3w4Fa?dl=0

This is much better than FR4, and the board houses say it handles like
FR4.


That is a lot better.

Cheers

Phil Hobbs

Nice crisp step, no ugly drool.

I\'ll try a 4-layer board for real. My SFP link thing is really
suffering from the FR4 losses.

Simon and I were TDRing a transmission line sample on an FR4 board
today. It\'s a time stretcher for geophysical lidar--24 T/Hs with about
50 ps aperture time, made of SAV-581+ pHEMTs. Each hold cap sits right
on an input of a simultaneous-sampling ADC. The gates are driven by
FIN1002 LVDS receivers via a very small Schottky diode, and are
forward-biased a bit in track mode. One input of each FIN comes from a
DAC output, and the other from a ~10-ns RC ramp. (There are two ramp
generators.)

The ramp lines are actually the parlour trick--ringing caused by all the
input reflections has to be managed carefully.

(Positively Larkinesque.)

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com

 

[John Larkin]

On Thu, 22 Oct 2020 18:45:21 -0400, Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:

On 2020-10-22 18:09, John Larkin wrote:
On Thu, 22 Oct 2020 17:51:10 -0400, Phil Hobbs
pcdhSpamMeSenseless@electrooptical.net> wrote:

On 2020-10-22 17:13, John Larkin wrote:


I only needed 3 square inches, but they sampled me a full panel. Good,
I\'ll have some around for fast protos.

https://www.dropbox.com/sh/fva424mq477k857/AACy1-4WS7yddHNOKpeg3w4Fa?dl=0

This is much better than FR4, and the board houses say it handles like
FR4.


That is a lot better.

Cheers

Phil Hobbs

Nice crisp step, no ugly drool.

I\'ll try a 4-layer board for real. My SFP link thing is really
suffering from the FR4 losses.




Simon and I were TDRing a transmission line sample on an FR4 board
today. It\'s a time stretcher for geophysical lidar--24 T/Hs with about
50 ps aperture time, made of SAV-581+ pHEMTs. Each hold cap sits right
on an input of a simultaneous-sampling ADC. The gates are driven by
FIN1002 LVDS receivers via a very small Schottky diode, and are
forward-biased a bit in track mode. One input of each FIN comes from a
DAC output, and the other from a ~10-ns RC ramp. (There are two ramp
generators.)

I can send you a hunk of the Isola. I have a whole panel. It seems to
have a working dielectric constant about 3.5, which makes traces
wider, which is generally good.

The ramp lines are actually the parlour trick--ringing caused by all the
input reflections has to be managed carefully.

(Positively Larkinesque.)

Hang on, I\'m counting how many rules you are breaking.

Cheers

Phil Hobbs

Send me a schematic, just for fun.

I was just talking to Miguel about this: nobody wants to do analog
design any more, and the guys in the big companies who used to do it
have mostly retired. More biz for us, I guess.

Fast stuff is especially exotic. People quake at the n-word, and
absolutely panic at the p-word. We have f-worded some.

Crossover, using RF/microwave specified parts in time domain, is
special fun. Let\'s not tell anyone that it\'s possible.

 

[Bill Sloman]

On Friday, October 23, 2020 at 9:59:31 AM UTC+11, John Larkin wrote:

On Thu, 22 Oct 2020 18:45:21 -0400, Phil Hobbs
pcdhSpamM...@electrooptical.net> wrote:

On 2020-10-22 18:09, John Larkin wrote:
On Thu, 22 Oct 2020 17:51:10 -0400, Phil Hobbs
pcdhSpamM...@electrooptical.net> wrote:

On 2020-10-22 17:13, John Larkin wrote:


I only needed 3 square inches, but they sampled me a full panel. Good,
I\'ll have some around for fast protos.

https://www.dropbox.com/sh/fva424mq477k857/AACy1-4WS7yddHNOKpeg3w4Fa?dl=0

This is much better than FR4, and the board houses say it handles like
FR4.


That is a lot better.

Cheers

Phil Hobbs

Nice crisp step, no ugly drool.

I\'ll try a 4-layer board for real. My SFP link thing is really
suffering from the FR4 losses.




Simon and I were TDRing a transmission line sample on an FR4 board
today. It\'s a time stretcher for geophysical lidar--24 T/Hs with about
50 ps aperture time, made of SAV-581+ pHEMTs. Each hold cap sits right
on an input of a simultaneous-sampling ADC. The gates are driven by
FIN1002 LVDS receivers via a very small Schottky diode, and are
forward-biased a bit in track mode. One input of each FIN comes from a
DAC output, and the other from a ~10-ns RC ramp. (There are two ramp
generators.)
I can send you a hunk of the Isola. I have a whole panel. It seems to
have a working dielectric constant about 3.5, which makes traces
wider, which is generally good.

The ramp lines are actually the parlour trick--ringing caused by all the
input reflections has to be managed carefully.

(Positively Larkinesque.)
Hang on, I\'m counting how many rules you are breaking.


Cheers

Phil Hobbs

Send me a schematic, just for fun.

I was just talking to Miguel about this: nobody wants to do analog
design any more, and the guys in the big companies who used to do it
have mostly retired. More biz for us, I guess.

Fast stuff is especially exotic. People quake at the n-word, and
absolutely panic at the p-word. We have f-worded some.

Crossover, using RF/microwave specified parts in time domain, is
special fun. Let\'s not tell anyone that it\'s possible.

I did some of that around 1984, in Cambridge, UK. Word has finally reached California?

Come to think of it

Ghiggino, K.P., Phillips, D., and Sloman, A.W. \"Nanosecond pulse stretcher\",Journal of Physics E: Scientific Instruments, 12, 686-687 (1979).

used a BFT95 5GHz broadband transistor in a simple emitter-coupled monostable. I was working in west London at the time, but it was for a group at the University of
Southampton.

John Larkin is trying to shut the stable door forty years after the horse had bolted.

--
Bill Sloman, Sydney

 

[Flyguy]

On Thursday, October 22, 2020 at 6:53:24 PM UTC-7, Bill Sloman wrote:

On Friday, October 23, 2020 at 9:59:31 AM UTC+11, John Larkin wrote:
On Thu, 22 Oct 2020 18:45:21 -0400, Phil Hobbs
pcdhSpamM...@electrooptical.net> wrote:

On 2020-10-22 18:09, John Larkin wrote:
On Thu, 22 Oct 2020 17:51:10 -0400, Phil Hobbs
pcdhSpamM...@electrooptical.net> wrote:

On 2020-10-22 17:13, John Larkin wrote:


I only needed 3 square inches, but they sampled me a full panel. Good,
I\'ll have some around for fast protos.

https://www.dropbox.com/sh/fva424mq477k857/AACy1-4WS7yddHNOKpeg3w4Fa?dl=0

This is much better than FR4, and the board houses say it handles like
FR4.


That is a lot better.

Cheers

Phil Hobbs

Nice crisp step, no ugly drool.

I\'ll try a 4-layer board for real. My SFP link thing is really
suffering from the FR4 losses.




Simon and I were TDRing a transmission line sample on an FR4 board
today. It\'s a time stretcher for geophysical lidar--24 T/Hs with about
50 ps aperture time, made of SAV-581+ pHEMTs. Each hold cap sits right
on an input of a simultaneous-sampling ADC. The gates are driven by
FIN1002 LVDS receivers via a very small Schottky diode, and are
forward-biased a bit in track mode. One input of each FIN comes from a
DAC output, and the other from a ~10-ns RC ramp. (There are two ramp
generators.)
I can send you a hunk of the Isola. I have a whole panel. It seems to
have a working dielectric constant about 3.5, which makes traces
wider, which is generally good.

The ramp lines are actually the parlour trick--ringing caused by all the
input reflections has to be managed carefully.

(Positively Larkinesque.)
Hang on, I\'m counting how many rules you are breaking.


Cheers

Phil Hobbs

Send me a schematic, just for fun.

I was just talking to Miguel about this: nobody wants to do analog
design any more, and the guys in the big companies who used to do it
have mostly retired. More biz for us, I guess.

Fast stuff is especially exotic. People quake at the n-word, and
absolutely panic at the p-word. We have f-worded some.

Crossover, using RF/microwave specified parts in time domain, is
special fun. Let\'s not tell anyone that it\'s possible.

I did some of that around 1984, in Cambridge, UK. Word has finally reached California?

Come to think of it

Ghiggino, K.P., Phillips, D., and Sloman, A.W. \"Nanosecond pulse stretcher\",Journal of Physics E: Scientific Instruments, 12, 686-687 (1979).

used a BFT95 5GHz broadband transistor in a simple emitter-coupled monostable. I was working in west London at the time, but it was for a group at the University of
Southampton.

John Larkin is trying to shut the stable door forty years after the horse had bolted.

--
SL0W MAN, Sydney

Hey SL0W MAN, you just can\'t RESIST posting ad-hominem bullshit about John even when it is TOTALLY out of context, can you? Just shows what an ASSHOLE you are!

 

[Bill Sloman]

On Friday, October 23, 2020 at 3:31:15 PM UTC+11, Flyguy wrote:

On Thursday, October 22, 2020 at 6:53:24 PM UTC-7, Bill Sloman wrote:
On Friday, October 23, 2020 at 9:59:31 AM UTC+11, John Larkin wrote:
On Thu, 22 Oct 2020 18:45:21 -0400, Phil Hobbs
pcdhSpamM...@electrooptical.net> wrote:

On 2020-10-22 18:09, John Larkin wrote:
On Thu, 22 Oct 2020 17:51:10 -0400, Phil Hobbs
pcdhSpamM...@electrooptical.net> wrote:

On 2020-10-22 17:13, John Larkin wrote:


I only needed 3 square inches, but they sampled me a full panel. Good,
I\'ll have some around for fast protos.

https://www.dropbox.com/sh/fva424mq477k857/AACy1-4WS7yddHNOKpeg3w4Fa?dl=0

This is much better than FR4, and the board houses say it handles like
FR4.


That is a lot better.

Cheers

Phil Hobbs

Nice crisp step, no ugly drool.

I\'ll try a 4-layer board for real. My SFP link thing is really
suffering from the FR4 losses.




Simon and I were TDRing a transmission line sample on an FR4 board
today. It\'s a time stretcher for geophysical lidar--24 T/Hs with about
50 ps aperture time, made of SAV-581+ pHEMTs. Each hold cap sits right
on an input of a simultaneous-sampling ADC. The gates are driven by
FIN1002 LVDS receivers via a very small Schottky diode, and are
forward-biased a bit in track mode. One input of each FIN comes from a
DAC output, and the other from a ~10-ns RC ramp. (There are two ramp
generators.)
I can send you a hunk of the Isola. I have a whole panel. It seems to
have a working dielectric constant about 3.5, which makes traces
wider, which is generally good.

The ramp lines are actually the parlour trick--ringing caused by all the
input reflections has to be managed carefully.

(Positively Larkinesque.)
Hang on, I\'m counting how many rules you are breaking.


Cheers

Phil Hobbs

Send me a schematic, just for fun.

I was just talking to Miguel about this: nobody wants to do analog
design any more, and the guys in the big companies who used to do it
have mostly retired. More biz for us, I guess.

Fast stuff is especially exotic. People quake at the n-word, and
absolutely panic at the p-word. We have f-worded some.

Crossover, using RF/microwave specified parts in time domain, is
special fun. Let\'s not tell anyone that it\'s possible.

I did some of that around 1984, in Cambridge, UK. Word has finally reached California?

Come to think of it

Ghiggino, K.P., Phillips, D., and Sloman, A.W. \"Nanosecond pulse stretcher\",Journal of Physics E: Scientific Instruments, 12, 686-687 (1979).

used a BFT95 5GHz broadband transistor in a simple emitter-coupled monostable. I was working in west London at the time, but it was for a group at the University of
Southampton.

John Larkin is trying to shut the stable door forty years after the horse had bolted.

Hey SL0W MAN, you just can\'t RESIST posting ad-hominem bullshit about John

What makes you think he is human?

> even when it is TOTALLY out of context, can you?

Flyguy doesn\'t understand the context.\"Using RF/microwave specified parts in time domain\" is clearly quite beyond him. John Larkin may think that he has discovered this trick himself, but in fact he\'s decades behind the rest of the field. I can document it with things I\'ve done. If we\'d thought we were doing anything new, somebody would have tried to patent it, but nobody bothered, so it has to have been around for rather longer.

> Just shows what an ASSHOLE you are!

Flyguy has his permanent and inflexible conclusion. He\'s not quite up to reasoning his way to it.

--
Bill Sloman. Sydney

 

[John S]

On 10/22/2020 11:31 PM, Flyguy wrote:

On Thursday, October 22, 2020 at 6:53:24 PM UTC-7, Bill Sloman wrote:
On Friday, October 23, 2020 at 9:59:31 AM UTC+11, John Larkin wrote:
On Thu, 22 Oct 2020 18:45:21 -0400, Phil Hobbs
pcdhSpamM...@electrooptical.net> wrote:

On 2020-10-22 18:09, John Larkin wrote:
On Thu, 22 Oct 2020 17:51:10 -0400, Phil Hobbs
pcdhSpamM...@electrooptical.net> wrote:

On 2020-10-22 17:13, John Larkin wrote:


I only needed 3 square inches, but they sampled me a full panel. Good,
I\'ll have some around for fast protos.

https://www.dropbox.com/sh/fva424mq477k857/AACy1-4WS7yddHNOKpeg3w4Fa?dl=0

This is much better than FR4, and the board houses say it handles like
FR4.


That is a lot better.

Cheers

Phil Hobbs

Nice crisp step, no ugly drool.

I\'ll try a 4-layer board for real. My SFP link thing is really
suffering from the FR4 losses.




Simon and I were TDRing a transmission line sample on an FR4 board
today. It\'s a time stretcher for geophysical lidar--24 T/Hs with about
50 ps aperture time, made of SAV-581+ pHEMTs. Each hold cap sits right
on an input of a simultaneous-sampling ADC. The gates are driven by
FIN1002 LVDS receivers via a very small Schottky diode, and are
forward-biased a bit in track mode. One input of each FIN comes from a
DAC output, and the other from a ~10-ns RC ramp. (There are two ramp
generators.)
I can send you a hunk of the Isola. I have a whole panel. It seems to
have a working dielectric constant about 3.5, which makes traces
wider, which is generally good.

The ramp lines are actually the parlour trick--ringing caused by all the
input reflections has to be managed carefully.

(Positively Larkinesque.)
Hang on, I\'m counting how many rules you are breaking.


Cheers

Phil Hobbs

Send me a schematic, just for fun.

I was just talking to Miguel about this: nobody wants to do analog
design any more, and the guys in the big companies who used to do it
have mostly retired. More biz for us, I guess.

Fast stuff is especially exotic. People quake at the n-word, and
absolutely panic at the p-word. We have f-worded some.

Crossover, using RF/microwave specified parts in time domain, is
special fun. Let\'s not tell anyone that it\'s possible.

I did some of that around 1984, in Cambridge, UK. Word has finally reached California?

Come to think of it

Ghiggino, K.P., Phillips, D., and Sloman, A.W. \"Nanosecond pulse stretcher\",Journal of Physics E: Scientific Instruments, 12, 686-687 (1979).

used a BFT95 5GHz broadband transistor in a simple emitter-coupled monostable. I was working in west London at the time, but it was for a group at the University of
Southampton.

John Larkin is trying to shut the stable door forty years after the horse had bolted.

--
SL0W MAN, Sydney

Hey SL0W MAN, you just can\'t RESIST posting ad-hominem bullshit about John even when it is TOTALLY out of context, can you? Just shows what an ASSHOLE you are!

+1

 

[Phil Hobbs]

On 2020-10-22 18:59, John Larkin wrote:

On Thu, 22 Oct 2020 18:45:21 -0400, Phil Hobbs
pcdhSpamMeSenseless@electrooptical.net> wrote:

On 2020-10-22 18:09, John Larkin wrote:
On Thu, 22 Oct 2020 17:51:10 -0400, Phil Hobbs
pcdhSpamMeSenseless@electrooptical.net> wrote:

On 2020-10-22 17:13, John Larkin wrote:


I only needed 3 square inches, but they sampled me a full panel. Good,
I\'ll have some around for fast protos.

https://www.dropbox.com/sh/fva424mq477k857/AACy1-4WS7yddHNOKpeg3w4Fa?dl=0

This is much better than FR4, and the board houses say it handles like
FR4.


That is a lot better.

Cheers

Phil Hobbs

Nice crisp step, no ugly drool.

I\'ll try a 4-layer board for real. My SFP link thing is really
suffering from the FR4 losses.




Simon and I were TDRing a transmission line sample on an FR4 board
today. It\'s a time stretcher for geophysical lidar--24 T/Hs with about
50 ps aperture time, made of SAV-581+ pHEMTs. Each hold cap sits right
on an input of a simultaneous-sampling ADC. The gates are driven by
FIN1002 LVDS receivers via a very small Schottky diode, and are
forward-biased a bit in track mode. One input of each FIN comes from a
DAC output, and the other from a ~10-ns RC ramp. (There are two ramp
generators.)

I can send you a hunk of the Isola. I have a whole panel. It seems to
have a working dielectric constant about 3.5, which makes traces
wider, which is generally good.


The ramp lines are actually the parlour trick--ringing caused by all the
input reflections has to be managed carefully.

(Positively Larkinesque.)

Hang on, I\'m counting how many rules you are breaking.


Cheers

Phil Hobbs

Send me a schematic, just for fun.

Sent.

I was just talking to Miguel about this: nobody wants to do analog
design any more, and the guys in the big companies who used to do it
have mostly retired. More biz for us, I guess.

Assuming my health holds out, I\'m planning to keep doing it for at least
another 15 years. Gizmo-building is way more fun than golf or
TV-watching or model trains or whatever it is that retired guys do.
(Okay, Joerg brews beer. That has its points, but it\'s a bit like
watching paint dry. Of course he gets his suicidal thrills on his bike.)

Fast stuff is especially exotic. People quake at the n-word, and
absolutely panic at the p-word. We have f-worded some.

Before boat anchors became cheap, that was not an entirely unreasonable
stance.

Crossover, using RF/microwave specified parts in time domain, is
special fun. Let\'s not tell anyone that it\'s possible.

Yeah. Trouble is, when doing that you have to buy volume, and a reel of
SAV-551+es is four grand or something. I\'m going to have a whack at
using the 40-GHz Renesas pHEMTs one of these times. I bet they\'re not
as stable as a SAV-551+.

Cheers

Phil Hobbs


--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com

 

[Phil Hobbs]

On 2020-10-23 00:31, Flyguy wrote:

On Thursday, October 22, 2020 at 6:53:24 PM UTC-7, Bill Sloman wrote:
snip
Crossover, using RF/microwave specified parts in time domain, is
special fun. Let\'s not tell anyone that it\'s possible.

I did some of that around 1984, in Cambridge, UK. Word has finally reached California?

Come to think of it

Ghiggino, K.P., Phillips, D., and Sloman, A.W. \"Nanosecond pulse stretcher\",Journal of Physics E: Scientific Instruments, 12, 686-687 (1979).

used a BFT95 5GHz broadband transistor in a simple emitter-coupled monostable. I was working in west London at the time, but it was for a group at the University of
Southampton.

John Larkin is trying to shut the stable door forty years after the horse had bolted.

--
SL0W MAN, Sydney

Hey SL0W MAN, you just can\'t RESIST posting ad-hominem bullshit about John even when it is TOTALLY out of context, can you? Just shows what an ASSHOLE you are!

FG,

It would be nice if you could refrain from reposting BS\'s BS. It\'s sort
of like cross-modulation due to a corroded antenna that lets it get by
the trap.

Thanks

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com

 

[server]

On Fri, 23 Oct 2020 10:05:12 -0400, Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:

On 2020-10-22 18:59, John Larkin wrote:
On Thu, 22 Oct 2020 18:45:21 -0400, Phil Hobbs
pcdhSpamMeSenseless@electrooptical.net> wrote:

On 2020-10-22 18:09, John Larkin wrote:
On Thu, 22 Oct 2020 17:51:10 -0400, Phil Hobbs
pcdhSpamMeSenseless@electrooptical.net> wrote:

On 2020-10-22 17:13, John Larkin wrote:


I only needed 3 square inches, but they sampled me a full panel. Good,
I\'ll have some around for fast protos.

https://www.dropbox.com/sh/fva424mq477k857/AACy1-4WS7yddHNOKpeg3w4Fa?dl=0

This is much better than FR4, and the board houses say it handles like
FR4.


That is a lot better.

Cheers

Phil Hobbs

Nice crisp step, no ugly drool.

I\'ll try a 4-layer board for real. My SFP link thing is really
suffering from the FR4 losses.




Simon and I were TDRing a transmission line sample on an FR4 board
today. It\'s a time stretcher for geophysical lidar--24 T/Hs with about
50 ps aperture time, made of SAV-581+ pHEMTs. Each hold cap sits right
on an input of a simultaneous-sampling ADC. The gates are driven by
FIN1002 LVDS receivers via a very small Schottky diode, and are
forward-biased a bit in track mode. One input of each FIN comes from a
DAC output, and the other from a ~10-ns RC ramp. (There are two ramp
generators.)

I can send you a hunk of the Isola. I have a whole panel. It seems to
have a working dielectric constant about 3.5, which makes traces
wider, which is generally good.


The ramp lines are actually the parlour trick--ringing caused by all the
input reflections has to be managed carefully.

(Positively Larkinesque.)

Hang on, I\'m counting how many rules you are breaking.


Cheers

Phil Hobbs

Send me a schematic, just for fun.

Sent.

Cool.

Ah, you are fine-tuning a power supply with a DAC. I\'m doing that too.
Desperate times and all that.

We did sort of the reverse of multiple s/h channels, for the NIF beam
modulators. We summed 120 gaussian impulses, one every 250 ps, each
with a DAC for amplitude, to make an arbitrary waveform generator. I
learned about Gibbs Ears.

https://www.dropbox.com/s/lpkbxe0renmr09e/Seg_Gen.JPG?raw=1

Nowadays there are fast DACs that can make the waveform they want. It
would be fun to redesign.



--

John Larkin Highland Technology, Inc

Science teaches us to doubt.

Claude Bernard

 

[John Larkin]

On Fri, 23 Oct 2020 10:19:35 -0400, Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:

On 2020-10-23 00:31, Flyguy wrote:
On Thursday, October 22, 2020 at 6:53:24 PM UTC-7, Bill Sloman wrote:
snip
Crossover, using RF/microwave specified parts in time domain, is
special fun. Let\'s not tell anyone that it\'s possible.

I did some of that around 1984, in Cambridge, UK. Word has finally reached California?

Come to think of it

Ghiggino, K.P., Phillips, D., and Sloman, A.W. \"Nanosecond pulse stretcher\",Journal of Physics E: Scientific Instruments, 12, 686-687 (1979).

used a BFT95 5GHz broadband transistor in a simple emitter-coupled monostable. I was working in west London at the time, but it was for a group at the University of
Southampton.

John Larkin is trying to shut the stable door forty years after the horse had bolted.

--
SL0W MAN, Sydney

Hey SL0W MAN, you just can\'t RESIST posting ad-hominem bullshit about John even when it is TOTALLY out of context, can you? Just shows what an ASSHOLE you are!

FG,

It would be nice if you could refrain from reposting BS\'s BS. It\'s sort
of like cross-modulation due to a corroded antenna that lets it get by
the trap.

Thanks

Phil Hobbs

PIM is interesting. All sorts of things happen at -150 dB down.

 

[John Larkin]

On Thu, 22 Oct 2020 14:13:00 -0700, John Larkin
<jlarkin@highland_atwork_technology.com> wrote:

I only needed 3 square inches, but they sampled me a full panel. Good,
I\'ll have some around for fast protos.

https://www.dropbox.com/sh/fva424mq477k857/AACy1-4WS7yddHNOKpeg3w4Fa?dl=0

This is much better than FR4, and the board houses say it handles like
FR4.

Got some Rogers samples to test.

https://www.dropbox.com/s/gouc8yqwauhxq9a/Rogers_Sample.jpg?raw=1

It\'s a lot shinier than the Isola. I\'ll carve a TDR/TDT sample for
this too.

 

[Phil Hobbs]

On 2020-10-23 11:34, jlarkin@highlandsniptechnology.com wrote:

On Fri, 23 Oct 2020 10:05:12 -0400, Phil Hobbs
pcdhSpamMeSenseless@electrooptical.net> wrote:

On 2020-10-22 18:59, John Larkin wrote:
On Thu, 22 Oct 2020 18:45:21 -0400, Phil Hobbs
pcdhSpamMeSenseless@electrooptical.net> wrote:

On 2020-10-22 18:09, John Larkin wrote:
On Thu, 22 Oct 2020 17:51:10 -0400, Phil Hobbs
pcdhSpamMeSenseless@electrooptical.net> wrote:

On 2020-10-22 17:13, John Larkin wrote:


I only needed 3 square inches, but they sampled me a full panel. Good,
I\'ll have some around for fast protos.

https://www.dropbox.com/sh/fva424mq477k857/AACy1-4WS7yddHNOKpeg3w4Fa?dl=0

This is much better than FR4, and the board houses say it handles like
FR4.


That is a lot better.

Cheers

Phil Hobbs

Nice crisp step, no ugly drool.

I\'ll try a 4-layer board for real. My SFP link thing is really
suffering from the FR4 losses.




Simon and I were TDRing a transmission line sample on an FR4 board
today. It\'s a time stretcher for geophysical lidar--24 T/Hs with about
50 ps aperture time, made of SAV-581+ pHEMTs. Each hold cap sits right
on an input of a simultaneous-sampling ADC. The gates are driven by
FIN1002 LVDS receivers via a very small Schottky diode, and are
forward-biased a bit in track mode. One input of each FIN comes from a
DAC output, and the other from a ~10-ns RC ramp. (There are two ramp
generators.)

I can send you a hunk of the Isola. I have a whole panel. It seems to
have a working dielectric constant about 3.5, which makes traces
wider, which is generally good.


The ramp lines are actually the parlour trick--ringing caused by all the
input reflections has to be managed carefully.

(Positively Larkinesque.)

Hang on, I\'m counting how many rules you are breaking.

Send me a schematic, just for fun.

Sent.


Cool.

Ah, you are fine-tuning a power supply with a DAC. I\'m doing that too.
Desperate times and all that.

We do that fairly routinely for Class-H TEC drivers.

This board has three very nice octal 8-bit DACs (DAC088S885, $2ish),
that set the thresholds for each of the 24 FIN1002 LVDS receivers that
control the SAV-581+ sampling gates. Each hold cap sits right on an
input of one of the four LTC2351CUH-14 6-channel, 14-bit
simultaneous-sampling ADCs.

It\'s strictly the bigger-hammer approach, but still a whole lot cheaper
than a 14-bit, 4 GS/s transient digitizer when you need range resolution
of an inch or two, but your rep rate is a kilohertz. We\'re getting ten
of them stuffed right now--the initial use is for a DoD SBIR project
we\'re subbing on, but I expect it\'ll come in handy for jobs as diverse
as geophysics and mapping swarms of honeybees. (We\'re waiting for word
on a grant proposal to do that.) The DoD thing is Phase 1, and assuming
Phase 2 and 3 get funded, we\'ll be helping some actual IC folks
implement the same general idea in an ASIC. (No, you can\'t have pHEMTs
on silicon ASICs, but the strays are so much lower that you almost
certainly don\'t need them for this sort of job.)

We did sort of the reverse of multiple s/h channels, for the NIF beam
modulators. We summed 120 gaussian impulses, one every 250 ps, each
with a DAC for amplitude, to make an arbitrary waveform generator. I
learned about Gibbs Ears.

https://www.dropbox.com/s/lpkbxe0renmr09e/Seg_Gen.JPG?raw=1

Nowadays there are fast DACs that can make the waveform they want. It
would be fun to redesign.

Fun!

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com

 

[Bill Sloman]

On Saturday, October 24, 2020 at 1:19:51 AM UTC+11, Phil Hobbs wrote:

On 2020-10-23 00:31, Flyguy wrote:
On Thursday, October 22, 2020 at 6:53:24 PM UTC-7, Bill Sloman wrote:
snip
Crossover, using RF/microwave specified parts in time domain, is
special fun. Let\'s not tell anyone that it\'s possible.

I did some of that around 1984, in Cambridge, UK. Word has finally reached California?

Come to think of it

Ghiggino, K.P., Phillips, D., and Sloman, A.W. \"Nanosecond pulse stretcher\",Journal of Physics E: Scientific Instruments, 12, 686-687 (1979).

used a BFT95 5GHz broadband transistor in a simple emitter-coupled monostable. I was working in west London at the time, but it was for a group at the University of
Southampton.

John Larkin is trying to shut the stable door forty years after the horse had bolted.

<snipped Flyguy being as stupid as ever>

> It would be nice if you could refrain from reposting BS\'s BS.

It wasn\'t BS. \"Crossover, using RF/microwave specified parts in time domain, is special fun. Let\'s not tell anyone that it\'s possible\" on the other hand, was.

> It\'s sort of like cross-modulation due to a corroded antenna that lets it get by the trap.

Having to flatter John Larkin is a different kind of trap.

--
Bill Sloman, Sydney

 

[Bill Sloman]

On Saturday, October 24, 2020 at 11:09:00 AM UTC+11, Phil Hobbs wrote:

On 2020-10-23 11:34, jla...@highlandsniptechnology.com wrote:
On Fri, 23 Oct 2020 10:05:12 -0400, Phil Hobbs
pcdhSpamM...@electrooptical.net> wrote:

On 2020-10-22 18:59, John Larkin wrote:
On Thu, 22 Oct 2020 18:45:21 -0400, Phil Hobbs
pcdhSpamM...@electrooptical.net> wrote:

On 2020-10-22 18:09, John Larkin wrote:
On Thu, 22 Oct 2020 17:51:10 -0400, Phil Hobbs
pcdhSpamM...@electrooptical.net> wrote:

On 2020-10-22 17:13, John Larkin wrote:

<snip>

We did sort of the reverse of multiple s/h channels, for the NIF beam
modulators. We summed 120 gaussian impulses, one every 250 ps, each
with a DAC for amplitude, to make an arbitrary waveform generator. I
learned about Gibbs Ears.

Gibb\'s oscillations

https://en.wikipedia.org/wiki/Gibbs_phenomenon

I found out about it - the hard way - back in 1978. I had to put a Hamming window on my FIR filter - realised as a long string of very precisely trimmed resistors, which meant re-doing the lot of them. The bats listening to the signal didn\'t care much, but making the published spectra look nice was important.

--
Bill Sloman, Sydney

 

[Piotr Wyderski]

John Larkin wrote:

I was just talking to Miguel about this: nobody wants to do analog
design any more, and the guys in the big companies who used to do it
have mostly retired. More biz for us, I guess.

Somebody still designs the multi-GHz scopes and remaining gear. One example:

https://www.keysight.com/en/pdx-2948607-pn-UXR0404A/infiniium-uxr-series-oscilloscope-40-ghz-4-channels?nid=-31885.1251400&cc=PL&lc=eng

Best regards, Piotr

 

[server]

On Sat, 24 Oct 2020 11:37:41 +0200, Piotr Wyderski
<peter.pan@neverland.mil> wrote:

John Larkin wrote:

I was just talking to Miguel about this: nobody wants to do analog
design any more, and the guys in the big companies who used to do it
have mostly retired. More biz for us, I guess.

Somebody still designs the multi-GHz scopes and remaining gear. One example:

https://www.keysight.com/en/pdx-2948607-pn-UXR0404A/infiniium-uxr-series-oscilloscope-40-ghz-4-channels?nid=-31885.1251400&cc=PL&lc=eng

Best regards, Piotr

I wonder if the 110 GHz version costs a million dollars.

Sure, some outfits are doing heavy-duty electronic design, but I think
there are fewer analog/circuit designers than there were. One of my
EEs is a recent grad and he says that his classmates avoided analog
electronics. They all want to type code, as in c or python or verilog.

Just my impression. I don\'t have serious statistics, just some
personal anecdotes.



--

John Larkin Highland Technology, Inc

Science teaches us to doubt.

Claude Bernard

 

[Fred Bloggs]

On Thursday, October 22, 2020 at 5:13:12 PM UTC-4, John Larkin wrote:

I only needed 3 square inches, but they sampled me a full panel. Good,
I\'ll have some around for fast protos.

https://www.dropbox.com/sh/fva424mq477k857/AACy1-4WS7yddHNOKpeg3w4Fa?dl=0

This is much better than FR4, and the board houses say it handles like
FR4.

Impossible to read the scale display on those images. Looks like FR4 and ISOLA 10-90% are the same at ~ 50ps. How sensitive is your design?