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Tom Gardner
Guest

Sun Jan 06, 2019 8:45 pm   



On 06/01/19 14:05, Kevin Aylward wrote:
Quote:
The vast majority of patents are worthless. Big companies don't care how much
they lose in getting patents for obvious ideas. They are just sticks to threaten
people with.


As I'm sure you are aware, there are five principal
reasons to get a patent:
1 an egoboost or career boost
2 to profit from the invention being used by others
3 so investors in a company have something "tangible"
to sell to another investor
4 pile 'em high patent portfolio swaps
5 to prevent other people patenting it and stopping you
from exploiting your invention

Some are more justifiable than others, and there
are cheaper ways to achieve the last one.

John Larkin
Guest

Sun Jan 06, 2019 8:45 pm   



On Sun, 6 Jan 2019 14:05:15 -0000, "Kevin Aylward"
<kevinRemovAT_at_kevinaylward.co.uk> wrote:

Quote:
wrote in message
news:c48dba3b-23d0-41d5-a19b-5aff21c7d598_at_googlegroups.com...

Its absolute impossible to design the oscillator itself with the required
ps
rejection. The oscillator is optimised for noise. 10,000 transistor are
used
to temp comp and linearize it. Its the ONLY way to do it in practice, at
high performance levels.

The only one that anybody has come up with so far.

Well.... I have been 10 years specifically designing oscillator ASICS, in a
company (Rakon) producing oscillators for 60 years, with a library stacked
with books on oscillator design. I have personally went through 100s of
topologies...

The issue with your comment, isn't that, sure, maybe there is a better
solution, but that it implies an unwarranted assumption that certain others
are too clueless to have come up with an optimum solution themselves.

As I said, it's *theoretically* impossible to design high stability
oscillators without regulating the ps, and its trivial to do the math to
prove this. "Captain, I cannie change the laws of physics, I need my 30
minutes."

We target 0.1ppb for a 5% ps change. If the current or voltage in an
oscillator changes, the frequency changes. Its that simple.

Many applications like quite a tight 50:50 duty cycle though. xtal
oscillators automatically give not a bad sine wave to drive the
limiter/squarer.

Crystal oscillators tend to have remarkably high Q-values, so the
sustaining current fed into them doesn't get the chance to generate much
non-sinusoidal voltage >across the crystal.

Well, sure....

The limiter is always the dominant flatband noise source.

But if you controlled the sustaining current more carefully you wouldn't
need a limiter.

This is not the limiting of the oscillator, it is the squaring up
*comparator* that converts the sine wave to rectangle. Its mandatory. to
have a square wave output.

The problem there is presumably the uncertainty of the position of the
edges of the square wave - a comparator is just a fast amplifier, and
amplifiers have input noise >which make the edge detection happen earlier
or later than it ideally should.
What you need is Percival distributed edge detector, where half a dozen
separate comparators look at progressively delayed version of the same
edge, and add the >delayed outputs together after further complementary
delays. Six of them would only give root six (2.45) reduction in the noise,
but that might be worth having - if you >have 10,000 transistors to play
with, a little redundancy is permissible.

Interesting idea, but not realistic in an ASIC. Transmission line delay
lines probably is the only way to generate delay without adding excessive
noise. Active delay amplifiers are a complete non starter, explained below.

Modern design needs solutions that exist in semiconductor ascic.

Similar things have been done in similar contexts.

The problem is the inherent noise of the comparator transistors.


Would it make sense to use a higher frequency crystal, then the
comparator, and divide the digital output? Or even a PLL and bandpass
filter, then the comparator? Faster edge rates into the comparator
reduce noise.

We did this series of tests by walking clock and data edges across one
another into a fast D-flop, and averaging the output states.

https://www.dropbox.com/s/1i2yz7otty94o9l/NB7_Jitter_1.jpg?dl=0

https://www.dropbox.com/s/qahpb8uh1xr53vj/NB7_Steps.jpg?dl=0

Jitters are around 50 fs RMS, some of which is probably artifacts of
the instrumentation.

The trick here being that we had fast edges going into the two ADI
comparators that generated the walking edges.

A passive bandpass filter could slam lots of voltage into a
comparator. But inductors are big.

--

John Larkin Highland Technology, Inc

lunatic fringe electronics

Tom Gardner
Guest

Sun Jan 06, 2019 9:45 pm   



On 06/01/19 19:45, Lasse Langwadt Christensen wrote:
Quote:
søndag den 6. januar 2019 kl. 20.38.57 UTC+1 skrev Tom Gardner:
On 06/01/19 14:05, Kevin Aylward wrote:
The vast majority of patents are worthless. Big companies don't care how much
they lose in getting patents for obvious ideas. They are just sticks to threaten
people with.

As I'm sure you are aware, there are five principal
reasons to get a patent:
1 an egoboost or career boost
2 to profit from the invention being used by others
3 so investors in a company have something "tangible"
to sell to another investor
4 pile 'em high patent portfolio swaps
5 to prevent other people patenting it and stopping you
from exploiting your invention

Some are more justifiable than others, and there
are cheaper ways to achieve the last one.

isn't five covered by selling stuff? i.e. if you can prove you have sold
something that does what someone later tries to patent it is considered
prior art and can't be patented


IANAL, but the essence of patents is disclosure
of the techniques involved. I doubt simply selling
an item is sufficient. OTOH publishing a technique
certainly is sufficient, and is much cheaper.

I believe there are publications regarded as
normal channels for that. I doubt anyone reads
them, so it might be considered "security
through obscurity".

Lasse Langwadt Christense
Guest

Sun Jan 06, 2019 9:45 pm   



søndag den 6. januar 2019 kl. 20.38.57 UTC+1 skrev Tom Gardner:
Quote:
On 06/01/19 14:05, Kevin Aylward wrote:
The vast majority of patents are worthless. Big companies don't care how much
they lose in getting patents for obvious ideas. They are just sticks to threaten
people with.

As I'm sure you are aware, there are five principal
reasons to get a patent:
1 an egoboost or career boost
2 to profit from the invention being used by others
3 so investors in a company have something "tangible"
to sell to another investor
4 pile 'em high patent portfolio swaps
5 to prevent other people patenting it and stopping you
from exploiting your invention

Some are more justifiable than others, and there
are cheaper ways to achieve the last one.


isn't five covered by selling stuff? i.e. if you can prove you have sold
something that does what someone later tries to patent it is considered
prior art and can't be patented

Lasse Langwadt Christense
Guest

Sun Jan 06, 2019 9:45 pm   



søndag den 6. januar 2019 kl. 21.22.28 UTC+1 skrev Tom Gardner:
Quote:
On 06/01/19 19:45, Lasse Langwadt Christensen wrote:
søndag den 6. januar 2019 kl. 20.38.57 UTC+1 skrev Tom Gardner:
On 06/01/19 14:05, Kevin Aylward wrote:
The vast majority of patents are worthless. Big companies don't care how much
they lose in getting patents for obvious ideas. They are just sticks to threaten
people with.

As I'm sure you are aware, there are five principal
reasons to get a patent:
1 an egoboost or career boost
2 to profit from the invention being used by others
3 so investors in a company have something "tangible"
to sell to another investor
4 pile 'em high patent portfolio swaps
5 to prevent other people patenting it and stopping you
from exploiting your invention

Some are more justifiable than others, and there
are cheaper ways to achieve the last one.

isn't five covered by selling stuff? i.e. if you can prove you have sold
something that does what someone later tries to patent it is considered
prior art and can't be patented

IANAL, but the essence of patents is disclosure
of the techniques involved. I doubt simply selling
an item is sufficient. OTOH publishing a technique
certainly is sufficient, and is much cheaper.

I believe there are publications regarded as
normal channels for that. I doubt anyone reads
them, so it might be considered "security
through obscurity".


IANAL either but,

https://www.iusmentis.com/patents/priorart/

Kevin Aylward
Guest

Sun Jan 06, 2019 10:45 pm   



"John Larkin" wrote in message
news:70l43e9tsdnse4bcdkcq07v74ovd43cjap_at_4ax.com...


Quote:

The limiter is always the dominant flatband noise source.

But if you controlled the sustaining current more carefully you wouldn't
need a limiter.

This is not the limiting of the oscillator, it is the squaring up
*comparator* that converts the sine wave to rectangle. Its mandatory. to
have a square wave output.

The problem there is presumably the uncertainty of the position of the
edges of the square wave - a comparator is just a fast amplifier, and
amplifiers have input noise >which make the edge detection happen earlier
or later than it ideally should.
What you need is Percival distributed edge detector, where half a dozen
separate comparators look at progressively delayed version of the same
edge, and add the >delayed outputs together after further complementary
delays. Six of them would only give root six (2.45) reduction in the
noise,
but that might be worth having - if you >have 10,000 transistors to play
with, a little redundancy is permissible.

Interesting idea, but not realistic in an ASIC. Transmission line delay
lines probably is the only way to generate delay without adding excessive
noise. Active delay amplifiers are a complete non starter, explained below.

Modern design needs solutions that exist in semiconductor ascic.

Similar things have been done in similar contexts.

The problem is the inherent noise of the comparator transistors.

Would it make sense to use a higher frequency crystal, then the
comparator, and divide the digital output? Or even a PLL and bandpass
filter, then the comparator? Faster edge rates into the comparator
reduce noise.


A faster edge always help, however, the xtal frequency is usually chosen to
satisfy other criteria.

Aging is key. Low frequency ones age better because they are bigger. We use
3rd overtone in some products because of that. Make pulling a lot harder
though.

My asics do actually have selectable dividers of 2,4, 8 for other
purposes.


Quote:
We did this series of tests by walking clock and data edges across one
another into a fast D-flop, and averaging the output states.

https://www.dropbox.com/s/1i2yz7otty94o9l/NB7_Jitter_1.jpg?dl=0

https://www.dropbox.com/s/qahpb8uh1xr53vj/NB7_Steps.jpg?dl=0

Jitters are around 50 fs RMS, some of which is probably artifacts of
the instrumentation.


Very impressive rise times.

I am using a 0.18u process, so 50 ps is about the fastest possible.

Faster processes are not really useful, even if we could afford them,. They
don't have very good general noise performance.

Quote:
The trick here being that we had fast edges going into the two ADI
comparators that generated the walking edges.

A passive bandpass filter could slam lots of voltage into a
comparator. But inductors are big.


Yes, noiseless gain is an option... but no such thing as a free lunch...
large gain, makes the effective input capacitance of the comparator larger,
which buggers the noise...

Its interesting the effects that crop up when you *really* study the
problem.

The key close in noise determinator of a comparator/xtal oscillator system
is the input capacitance of the comparator being modulated by the 1/f noise
of the transistors in the comparator. Its a bit subtle, but easily checked
in simulation.

The comparator is fed from the xtal load capacitance, so the comparator
input capacitance forms part of the oscillator loop. It is direct frequency
modulation. In simulations, you can look at the phase noise at the input (as
apart from the output), and Cadence spits out a table of what transistor
generates what % of noise. Its the nonlinear voltages and currents that are
modulated by the noise of the transistors, which modulate the effective
capacitances formed by miller gains and emitter follower loads etc....in the
comparator. Note that the xtal load capacitors are only 10pF -20pF.


-- Kevin Aylward
http://www.anasoft.co.uk - SuperSpice
http://www.kevinaylward.co.uk/ee/index.html


Guest

Sun Jan 06, 2019 11:45 pm   



On Sunday, 6 January 2019 20:22:28 UTC, Tom Gardner wrote:

Quote:
As I'm sure you are aware, there are five principal
reasons to get a patent:
1 an egoboost or career boost
2 to profit from the invention being used by others
3 so investors in a company have something "tangible"
to sell to another investor
4 pile 'em high patent portfolio swaps
5 to prevent other people patenting it and stopping you
from exploiting your invention

Some are more justifiable than others, and there
are cheaper ways to achieve the last one.

isn't five covered by selling stuff? i.e. if you can prove you have sold
something that does what someone later tries to patent it is considered
prior art and can't be patented

IANAL, but the essence of patents is disclosure
of the techniques involved. I doubt simply selling
an item is sufficient.


It's sufficient to make something unpatentable in principle. But that hasn't stopped eg Mr Bayliss patenting a clockwork motor driving an electric motor, something loads of us did as kids.


Quote:
OTOH publishing a technique
certainly is sufficient, and is much cheaper.


if you don't want exclusivity or saleability of the technology, sure


NT

Quote:
I believe there are publications regarded as
normal channels for that. I doubt anyone reads
them, so it might be considered "security
through obscurity".


Tom Gardner
Guest

Mon Jan 07, 2019 12:45 am   



On 06/01/19 20:36, Lasse Langwadt Christensen wrote:
Quote:
søndag den 6. januar 2019 kl. 21.22.28 UTC+1 skrev Tom Gardner:
On 06/01/19 19:45, Lasse Langwadt Christensen wrote:
søndag den 6. januar 2019 kl. 20.38.57 UTC+1 skrev Tom Gardner:
On 06/01/19 14:05, Kevin Aylward wrote:
The vast majority of patents are worthless. Big companies don't care how much
they lose in getting patents for obvious ideas. They are just sticks to threaten
people with.

As I'm sure you are aware, there are five principal
reasons to get a patent:
1 an egoboost or career boost
2 to profit from the invention being used by others
3 so investors in a company have something "tangible"
to sell to another investor
4 pile 'em high patent portfolio swaps
5 to prevent other people patenting it and stopping you
from exploiting your invention

Some are more justifiable than others, and there
are cheaper ways to achieve the last one.

isn't five covered by selling stuff? i.e. if you can prove you have sold
something that does what someone later tries to patent it is considered
prior art and can't be patented

IANAL, but the essence of patents is disclosure
of the techniques involved. I doubt simply selling
an item is sufficient. OTOH publishing a technique
certainly is sufficient, and is much cheaper.

I believe there are publications regarded as
normal channels for that. I doubt anyone reads
them, so it might be considered "security
through obscurity".

IANAL either but,

https://www.iusmentis.com/patents/priorart/


Indeed, provided the invention is, in some way
or other, demonstrably visible. That can be
very difficult to prove, especially with
"invisible" embedded software.


Guest

Mon Jan 07, 2019 4:45 am   



On Monday, January 7, 2019 at 1:05:26 AM UTC+11, Kevin Aylward wrote:
Quote:
wrote in message
news:c48dba3b-23d0-41d5-a19b-5aff21c7d598_at_googlegroups.com...

Its absolute impossible to design the oscillator itself with the required
ps
rejection. The oscillator is optimised for noise. 10,000 transistor are
used
to temp comp and linearize it. Its the ONLY way to do it in practice, at
high performance levels.

The only one that anybody has come up with so far.

Well.... I have been 10 years specifically designing oscillator ASICS, in a
company (Rakon) producing oscillators for 60 years, with a library stacked
with books on oscillator design. I have personally went through 100s of
topologies...

The issue with your comment, isn't that, sure, maybe there is a better
solution, but that it implies an unwarranted assumption that certain others
are too clueless to have come up with an optimum solution themselves.


It's not cluelessness, but rather a built-in set of assumptions that are embedded in that library of old designs.

Quote:
As I said, it's *theoretically* impossible to design high stability
oscillators without regulating the ps, and its trivial to do the math to
prove this. "Captain, I cannie change the laws of physics, I need my 30
minutes."

We target 0.1ppb for a 5% ps change. If the current or voltage in an
oscillator changes, the frequency changes. Its that simple.


With the oscillators you choose to work with. People who need serious oscillator stability rely on quantum physics to get what they need.

https://ws680.nist.gov/publication/get_pdf.cfm?pub_id=50217

This rubidium frequency standard isn't all the way there to a system on a chip, but its pretty compact.

Quote:
Many applications like quite a tight 50:50 duty cycle though. xtal
oscillators automatically give not a bad sine wave to drive the
limiter/squarer.

Crystal oscillators tend to have remarkably high Q-values, so the
sustaining current fed into them doesn't get the chance to generate much
non-sinusoidal voltage >across the crystal.

Well, sure....

The limiter is always the dominant flatband noise source.

But if you controlled the sustaining current more carefully you wouldn't
need a limiter.

This is not the limiting of the oscillator, it is the squaring up
*comparator* that converts the sine wave to rectangle. Its mandatory. to
have a square wave output.

The problem there is presumably the uncertainty of the position of the
edges of the square wave - a comparator is just a fast amplifier, and
amplifiers have input noise which make the edge detection happen earlier
or later than it ideally should.
What you need is Percival distributed edge detector, where half a dozen
separate comparators look at progressively delayed version of the same
edge, and add the >delayed outputs together after further complementary
delays. Six of them would only give root six (2.45) reduction in the noise,
but that might be worth having - if you >have 10,000 transistors to play
with, a little redundancy is permissible.

Interesting idea, but not realistic in an ASIC. Transmission line delay
lines probably is the only way to generate delay without adding excessive
noise. Active delay amplifiers are a complete non starter, explained below.

Modern design needs solutions that exist in semiconductor asic.


Tracks on ASICs can be configured as low loss transmission lines. Wasting enough silicon area to get enough delay (which wouldn't need to be much) may be an economic impossibility. but at least the tracks don't dissipate heat..

Quote:
Similar things have been done in similar contexts.

The problem is the inherent noise of the comparator transistors.


That's what I said.

Quote:
The input comes from a highly band-limited xtal filtered output. It can be
shown that an ideal band limited input to an ideal comparator, has the same
So/No as the Si/Ni. See for example:

https://www.springer.com/gb/book/9781402076664

The issue though, is that it is impossible to band limit the internal noise
of the limiting amplifier.


That's obvious.

Quote:
The net result is that the internal wideband
noise, generates around 12 dB more output phase noise than would be expected
from its amplitude noise. It's about power.

Every 1 mA might give about 1 Deg increase in temperature of an OCXO system.
A 5 deg increase might have the system running at 110 Deg instead of 105
Deg. Its a major problem for the xtal. A lot of systems have the xtal at,
maybe 90 Deg. The system loses regulation at its internal idle current
level.


So pay for a big chunk of silicon, or mount it on a chunk of thin film diamond to heat sink it better.

Quote:
The oscillator amplitude limiting to have the
gain equal to one is a different issue.

http://www.kevinaylward.co.uk/ee/phasenoise/phasenoise.html

You seem to be confident that you are onto something, but don't seem to be
able to find the words that make the idea intelligible.

Oh... well those ideas have generated designs with 12dB lower noise than the
competition.


But you can't explain why in a way that intelligible to anybody who isn't deep enough into the technology to be a direct competitor.

Quote:
So, yeah... I am on to something...and... its not my problem that others
don't understand the theory.


It is if you want to communicate the theory.

Quote:
I have previously done a lot of simulations on including and not
including the output buffer with the comp capacitor and always get
the same distortion for either condition.

But you aren't Bob Widlar or Barry Gilbert.

What's your point?

They seem to have been able to come up with unexpected solutions.
There weren't many people in the area who could do that - I can't think
of any others - but those two did exist.

..and your knowledge of my own professional career solutions to problems
is
what?

You don't boast about the patents that name you as an inventor, for
starters.

The best ideas are not always patented. Its called, keeping a secret.


Technically, a trade secret. I worked on electron beam testers, and if the secret is embedded in the silicon, and competitor with a suitably embellished electron microscope can read it.

Quote:
Seriously, there is no way I can post either my BG regulators that beat
commercial BG regulators by orders of magnitude, or my oscillator designs,
similarly 12 dB superior in noise to the competition, because they are not
patentable. However, clearly few, if any, are using the specific structures
and operating conditions the way that I am using them.

Bob Widlar and Barry Gilbert didn't have to - their names kept coming up in
patent searches.

I have seen many of their patents. Truly a waste of paper for most.


Generally true. Sturgeons Law was that 90% of everything is rubbish. The remaining 10% has been known to make people lots of money.

The trouble with patenting good ideas is that it is rarely clear which good idea will be marketable.

Quote:
I already noted that Gilbert had a design for a 3rd order approximate
chebychev function, this was actually in a patent he had. No competent
designer is going to use that approach in a high performance TCXO/OCXO. I
just don't have the time to go into all the technical aspects of ASIC
design.

Usually, a patent is where the author is simply unaware of how others solve
the same problem in a standard topology.


This happens, but a patent search is part of the patenting process. The examples I was confronted with didn't suggest that searchers were particularly expert.

Quote:
I spent a couple of years at EMI Central Research and got two patents out
of it - places like than (and IBM) patented pretty much everything they
could (even krw has got a couple patents out of his IBM time) but I did
get exposed to people who were seriously creative.

The vast majority of patents are worthless. Big companies don't care how
much they lose in getting patents for obvious ideas. They are just sticks to
threaten people with.


More negotiating chips in patent swaps. To some extent patenting everything you can can hide crucial patents that are important in a flood of less important paper-work, but the value of a patent isn't always obvious. One friend of mine patented an idea (for a better confocal microscope) that eventually made him millions, three weeks after Tektronix applied for a provisional patent on the same idea. Tektronix didn't follow up with a real patent (which would have cost them thousands of dollars) so my friend did get the patent.

--
Bill Sloman, Sydney

Kevin Aylward
Guest

Mon Jan 07, 2019 9:45 pm   



wrote in message
news:6fa45dff-4a16-424b-92fe-45751416910e_at_googlegroups.com...

On Monday, January 7, 2019 at 1:05:26 AM UTC+11, Kevin Aylward wrote:
Quote:
wrote in message
news:c48dba3b-23d0-41d5-a19b-5aff21c7d598_at_googlegroups.com...

Its absolute impossible to design the oscillator itself with the
required
ps
rejection. The oscillator is optimised for noise. 10,000 transistor are
used
to temp comp and linearize it. Its the ONLY way to do it in practice,
at
high performance levels.

The only one that anybody has come up with so far.

Well.... I have been 10 years specifically designing oscillator ASICS, in
a
company (Rakon) producing oscillators for 60 years, with a library stacked
with books on oscillator design. I have personally went through 100s of
topologies...

The issue with your comment, isn't that, sure, maybe there is a better
solution, but that it implies an unwarranted assumption that certain
others
are too clueless to have come up with an optimum solution themselves.

It's not cluelessness, but rather a built-in set of assumptions that are
embedded in that library of old designs.


....but apparently, your assumption here, is that other people are also too
clueless to not understand those assumptions either.

For example, I looked at the effort they did in the designs of 60 years ago
get better ps rejection. It was a no brainer that such effort would be
wasted today. We don't use vacuum tubes.

Quote:
As I said, it's *theoretically* impossible to design high stability
oscillators without regulating the ps, and its trivial to do the math to
prove this. "Captain, I cannie change the laws of physics, I need my 30
minutes."

We target 0.1ppb for a 5% ps change. If the current or voltage in an
oscillator changes, the frequency changes. Its that simple.

With the oscillators you choose to work with. People who need serious
oscillator stability rely on quantum physics to get what they need.


There are billions and billions of product unit sales targeting the
stability achievable by xtals. That's the market I'm in.


Quote:

The problem there is presumably the uncertainty of the position of the
edges of the square wave - a comparator is just a fast amplifier, and
amplifiers have input noise which make the edge detection happen earlier
or later than it ideally should.
What you need is Percival distributed edge detector, where half a dozen
separate comparators look at progressively delayed version of the same
edge, and add the >delayed outputs together after further complementary
delays. Six of them would only give root six (2.45) reduction in the
noise,
but that might be worth having - if you >have 10,000 transistors to play
with, a little redundancy is permissible.

Interesting idea, but not realistic in an ASIC. Transmission line delay
lines probably is the only way to generate delay without adding excessive
noise. Active delay amplifiers are a complete non starter, explained
below.

Modern design needs solutions that exist in semiconductor asic.

Tracks on ASICs can be configured as low loss transmission lines.
Wasting enough silicon area to get enough delay (which wouldn't need to be
much) may be an
economic impossibility.
but at least the tracks don't dissipate heat.


Not at 10MHz to 60MHz (which is where the best xtals are) though. Simply
not physically viable at those frequencies

You are really toiling to get a few nH on chip. I would say 1GHz is about
the point where inductors/T lines might make sense on an ASIC

I have looked at this for a 2G5 product, e.g. maybe 400um x 400um on a 1mm x
1mm chip is a big chunk.

5 layer metal helps for constructing spirals.

Quote:
The input comes from a highly band-limited xtal filtered output. It can
be
shown that an ideal band limited input to an ideal comparator, has the
same
So/No as the Si/Ni. See for example:

https://www.springer.com/gb/book/9781402076664

The issue though, is that it is impossible to band limit the internal
noise
of the limiting amplifier.

That's obvious.


But not readily apparent to those that wrote the book I referenced. They
made a big deal of proving that So/No=Si/Ni for a band limited input, and
based following ideas on that result. The result though is, essentially,
useless for designing real osc/limiter systems.

Quote:
The net result is that the internal wideband
noise, generates around 12 dB more output phase noise than would be
expected
from its amplitude noise. It's about power.

Every 1 mA might give about 1 Deg increase in temperature of an OCXO
system.
A 5 deg increase might have the system running at 110 Deg instead of 105
Deg. Its a major problem for the xtal. A lot of systems have the xtal at,
maybe 90 Deg. The system loses regulation at its internal idle current
level.

So pay for a big chunk of silicon, or mount it on a chunk of thin film
diamond to heat sink it better.


Ahmmmmmm...... and oh dear.....

All of the electronics are in a sealed package (xtal, sensor, asic). The
goal of the package design is to have as *large* a thermal resistance as
possible. Immense thermal modelling effort in COMSOL is done to achieve
this. Its why we have only 4 pins coming out from the package to *minimise*
heat loss.

Now... just why do you think that is done......?

No one wants to waste 10 Watts of power in an OCXO... This should be
obvious....

As it is, at -40 deg its about 0.5W, at around 200mA.

Everyone would like the power of a TCXO (few ma) , unfortunately TCXOs don't
cut it for all applications.

So... there are conflicting issues at low and high ambient temperature.

Quote:
The oscillator amplitude limiting to have the
gain equal to one is a different issue.

http://www.kevinaylward.co.uk/ee/phasenoise/phasenoise.html

You seem to be confident that you are onto something, but don't seem to
be
able to find the words that make the idea intelligible.

Oh... well those ideas have generated designs with 12dB lower noise than
the
competition.

But you can't explain why in a way that intelligible to anybody who isn't
deep enough into the technology to be a direct competitor.


I am not going to explain the specific details that I use at my place of
employment. However, I have posted generic technical details on my website
as to phase noise that many others seem to understand quite well.

Quote:
So, yeah... I am on to something...and... its not my problem that others
don't understand the theory.

It is if you want to communicate the theory.


I meant to say, "some others" not all. Many manage quite well with what I
write. Of course, there are some mathematically technicalitys that some may
not be acquainted with. I would suggest a book on Signal Analysis or Math
e.g. convolution theorem.


-- Kevin Aylward
http://www.anasoft.co.uk - SuperSpice
http://www.kevinaylward.co.uk/ee/index.html


Guest

Tue Jan 08, 2019 12:45 am   



On Tuesday, January 8, 2019 at 7:34:33 AM UTC+11, Kevin Aylward wrote:
Quote:
wrote in message
news:6fa45dff-4a16-424b-92fe-45751416910e_at_googlegroups.com...
On Monday, January 7, 2019 at 1:05:26 AM UTC+11, Kevin Aylward wrote:
wrote in message
news:c48dba3b-23d0-41d5-a19b-5aff21c7d598_at_googlegroups.com...


The issue with your comment, isn't that, sure, maybe there is a better
solution, but that it implies an unwarranted assumption that certain
others are too clueless to have come up with an optimum solution
themselves.

It's not cluelessness, but rather a built-in set of assumptions that are
embedded in that library of old designs.

...but apparently, your assumption here, is that other people are also too
clueless to not understand those assumptions either.


It's not a question of whether they understand them, but rather whether they bother to question them. "Not invented here" isn't an attitude that people adopt, but rather the human default setting.

Quote:
For example, I looked at the effort they did in the designs of 60 years ago
get better ps rejection. It was a no brainer that such effort would be
wasted today. We don't use vacuum tubes.


For excellent reasons. Most of the time.

Quote:
As I said, it's *theoretically* impossible to design high stability
oscillators without regulating the ps, and its trivial to do the math to
prove this. "Captain, I cannie change the laws of physics, I need my 30
minutes."

We target 0.1ppb for a 5% ps change. If the current or voltage in an
oscillator changes, the frequency changes. Its that simple.

With the oscillators you choose to work with. People who need serious
oscillator stability rely on quantum physics to get what they need.

There are billions and billions of product unit sales targeting the
stability achievable by xtals. That's the market I'm in.


Until somebody comes up with a way of achieving the same stability more cheaply.

<snip>

--
Bill Sloman, Sydney

Phil Hobbs
Guest

Tue Jan 08, 2019 1:45 am   



On 1/6/19 5:58 PM, Tom Gardner wrote:
Quote:
On 06/01/19 20:36, Lasse Langwadt Christensen wrote:
søndag den 6. januar 2019 kl. 21.22.28 UTC+1 skrev Tom Gardner:
On 06/01/19 19:45, Lasse Langwadt Christensen wrote:
søndag den 6. januar 2019 kl. 20.38.57 UTC+1 skrev Tom Gardner:
On 06/01/19 14:05, Kevin Aylward wrote:
The vast majority of patents are worthless. Big companies don't
care how much
they lose in getting patents for obvious ideas. They are just
sticks to threaten
people with.

As I'm sure you are aware, there are five principal
reasons to get a patent:
    1 an egoboost or career boost
    2 to profit from the invention being used by others
    3 so investors in a company have something "tangible"
      to sell to another investor
    4 pile 'em high patent portfolio swaps
    5 to prevent other people patenting it and stopping you
      from exploiting your invention

Some are more justifiable than others, and there
are cheaper ways to achieve the last one.

isn't five covered by selling stuff? i.e. if you can prove you have
sold
something that does what someone later tries to patent it is considered
prior art and can't be patented

IANAL, but the essence of patents is disclosure
of the techniques involved. I doubt simply selling
an item is sufficient. OTOH publishing a technique
certainly is sufficient, and is much cheaper.

I believe there are publications regarded as
normal channels for that. I doubt anyone reads
them, so it might be considered "security
through obscurity".

IANAL either but,

https://www.iusmentis.com/patents/priorart/

Indeed, provided the invention is, in some way
or other, demonstrably visible. That can be
very difficult to prove, especially with
"invisible" embedded software.


When there are hundreds of millions of dollars at stake, you'd be
surprised at what you can get done.

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
Guest

Tue Jan 08, 2019 1:45 am   



On 1/6/19 2:45 PM, Lasse Langwadt Christensen wrote:
Quote:
søndag den 6. januar 2019 kl. 20.38.57 UTC+1 skrev Tom Gardner:
On 06/01/19 14:05, Kevin Aylward wrote:
The vast majority of patents are worthless. Big companies don't care how much
they lose in getting patents for obvious ideas. They are just sticks to threaten
people with.

As I'm sure you are aware, there are five principal
reasons to get a patent:
1 an egoboost or career boost
2 to profit from the invention being used by others
3 so investors in a company have something "tangible"
to sell to another investor
4 pile 'em high patent portfolio swaps
5 to prevent other people patenting it and stopping you
from exploiting your invention

Some are more justifiable than others, and there
are cheaper ways to achieve the last one.

isn't five covered by selling stuff? i.e. if you can prove you have sold
something that does what someone later tries to patent it is considered
prior art and can't be patented


There's some interaction of patent and trade secret law involved with
that one. I'm not a lawyer, but AIUI anything that can be learned by
examination of a product offered for sale cannot be a trade secret.

If you have a real trade secret that somebody else patents, as far as I
know you're out of luck.

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
Guest

Tue Jan 08, 2019 1:45 am   



On 1/6/19 3:22 PM, Tom Gardner wrote:
Quote:
On 06/01/19 19:45, Lasse Langwadt Christensen wrote:
søndag den 6. januar 2019 kl. 20.38.57 UTC+1 skrev Tom Gardner:
On 06/01/19 14:05, Kevin Aylward wrote:
The vast majority of patents are worthless. Big companies don't
care how much they lose in getting patents for obvious ideas.
They are just sticks to threaten people with.

As I'm sure you are aware, there are five principal reasons to
get a patent: 1 an egoboost or career boost 2 to profit from the
invention being used by others 3 so investors in a company have
something "tangible" to sell to another investor 4 pile 'em high
patent portfolio swaps 5 to prevent other people patenting it and
stopping you from exploiting your invention

Some are more justifiable than others, and there are cheaper ways
to achieve the last one.

isn't five covered by selling stuff? i.e. if you can prove you have
sold something that does what someone later tries to patent it is
considered prior art and can't be patented

IANAL, but the essence of patents is disclosure of the techniques
involved. I doubt simply selling an item is sufficient.


Prior sale is a very strong defense against charges of patent
infringement. I spent a good part of today testing old hardware for
just that reason.

Quote:
OTOH publishing a technique certainly is sufficient, and is much
cheaper.

I believe there are publications regarded as normal channels for
that. I doubt anyone reads them, so it might be considered "security
through obscurity".


IBM has a journal like that, the IBM Patent Disclosure Bulletin.

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

Tom Gardner
Guest

Tue Jan 08, 2019 10:45 am   



On 08/01/19 00:24, Phil Hobbs wrote:
Quote:
On 1/6/19 3:22 PM, Tom Gardner wrote:
On 06/01/19 19:45, Lasse Langwadt Christensen wrote:
søndag den 6. januar 2019 kl. 20.38.57 UTC+1 skrev Tom Gardner:
On 06/01/19 14:05, Kevin Aylward wrote:
The vast majority of patents are worthless. Big companies don't
care how much they lose in getting patents for obvious ideas.
They are just sticks to threaten people with.

As I'm sure you are aware, there are five principal reasons to
get a patent: 1 an egoboost or career boost 2 to profit from the
invention being used by others 3 so investors in a company have
something "tangible" to sell to another investor 4 pile 'em high
patent portfolio swaps 5 to prevent other people patenting it and
stopping you from exploiting your invention

Some are more justifiable than others, and there are cheaper ways
to achieve the last one.

isn't five covered by selling stuff? i.e. if you can prove you have
sold something that does what someone later tries to patent it is
considered prior art and can't be patented

IANAL, but the essence of patents is disclosure of the techniques
involved. I doubt simply selling an item is sufficient.

Prior sale is a very strong defense against charges of patent
infringement.  I spent a good part of today testing old hardware for
just that reason.


I bow to someone with actual experience in the field.


Quote:
OTOH publishing a technique certainly is sufficient, and is much
cheaper.

I believe there are publications regarded as normal channels for
that. I doubt anyone reads them, so it might be considered "security through
obscurity".

IBM has a journal like that, the IBM Patent Disclosure Bulletin.


Unsurprising for IBM. I believe there are public equivalents
that can be used by anyone.

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