Discussion:
Yttrium iron garnet
(too old to reply)
Bill Sloman
2024-05-29 03:52:34 UTC
Permalink
John Larkin posted a schematic that included a featureless box that he
described as an ECL voltage controlled oscillator.

It was probably a voltage controlled crystal oscillator - a VCXO - or
perhaps a TCVCXO.

https://en.wikipedia.org/wiki/Voltage-controlled_oscillator

They now seem to go up to 800MHz and 1.2GHz which is a lot faster than
they were when I was interested.

https://www.qsl.net/n9zia/yig/yigintro.pdf

Yttrium iron garnet tuned oscillators were around back then, but their
2GHz to 8GHz range was too high for me to count with the integrated
circuits around then - we had to go the Gigabit Logic's GaAs parts to
get to 800MHz, and that became the unique selling point of the system.

The YIG resonance is narrow and depends linearly on the magnetic field
which can be controlled with some precision.

John should have done his precision timing by counting the edges of a
YIG generated clock - we now have counters that can go that fast, and
twiddled the frequency to get the exact time delay required.
--
Bill Sloman, Sydney
Cursitor Doom
2024-05-29 17:12:21 UTC
Permalink
Post by Bill Sloman
Yttrium iron garnet tuned oscillators were around back then, but their
2GHz to 8GHz range was too high for me to count with the integrated
circuits around then - we had to go the Gigabit Logic's GaAs parts to
get to 800MHz, and that became the unique selling point of the system.
YIG oscillators were quite the thing back in the day, but I'm guessing
they've been completely superseded by now to get to ever higher
frequencies. Seems we've gone from -

R/C to L/C to Xtal to YIG since about 1900. Did I miss any development(s)
out pre-YIG?
john larkin
2024-05-29 17:37:52 UTC
Permalink
On Wed, 29 May 2024 17:12:21 -0000 (UTC), Cursitor Doom
Post by Cursitor Doom
Post by Bill Sloman
Yttrium iron garnet tuned oscillators were around back then, but their
2GHz to 8GHz range was too high for me to count with the integrated
circuits around then - we had to go the Gigabit Logic's GaAs parts to
get to 800MHz, and that became the unique selling point of the system.
YIG oscillators were quite the thing back in the day, but I'm guessing
they've been completely superseded by now to get to ever higher
frequencies. Seems we've gone from -
R/C to L/C to Xtal to YIG since about 1900. Did I miss any development(s)
out pre-YIG?
Tuning forks, SAWs, BAWs, mechanical ceramic resonators, dielectric
ceramic resonators, coaxial ceramic resonators, sapphire, cavities,
atomic things.
Bill Sloman
2024-05-30 05:45:21 UTC
Permalink
Post by john larkin
On Wed, 29 May 2024 17:12:21 -0000 (UTC), Cursitor Doom
Post by Cursitor Doom
Post by Bill Sloman
Yttrium iron garnet tuned oscillators were around back then, but their
2GHz to 8GHz range was too high for me to count with the integrated
circuits around then - we had to go the Gigabit Logic's GaAs parts to
get to 800MHz, and that became the unique selling point of the system.
YIG oscillators were quite the thing back in the day, but I'm guessing
they've been completely superseded by now to get to ever higher
frequencies. Seems we've gone from -
This misses Jan Panteltje's thread "Small magnetic tunable filter for 6G
and beyond" which is about Yig being used today.
Post by john larkin
Post by Cursitor Doom
R/C to L/C to Xtal to YIG since about 1900. Did I miss any development(s)
out pre-YIG?
Tuning forks, SAWs, BAWs, mechanical ceramic resonators, dielectric
ceramic resonators, coaxial ceramic resonators, sapphire, cavities,
atomic things.
As usual, John Larkin hasn't noticed that most of his list can't be
rapidly tuned to a different frequency.
--
Bill Sloman, Sydney
Cursitor Doom
2024-05-30 09:14:58 UTC
Permalink
Post by Bill Sloman
Post by john larkin
On Wed, 29 May 2024 17:12:21 -0000 (UTC), Cursitor Doom
Post by Cursitor Doom
Post by Bill Sloman
Yttrium iron garnet tuned oscillators were around back then, but
their 2GHz to 8GHz range was too high for me to count with the
integrated circuits around then - we had to go the Gigabit Logic's
GaAs parts to get to 800MHz, and that became the unique selling point
of the system.
YIG oscillators were quite the thing back in the day, but I'm guessing
they've been completely superseded by now to get to ever higher
frequencies. Seems we've gone from -
This misses Jan Panteltje's thread "Small magnetic tunable filter for 6G
and beyond" which is about Yig being used today.
That article makes it seem like YIG is some revolutionary, new, emerging
technology!
Glen Walpert
2024-05-30 11:03:19 UTC
Permalink
Post by Cursitor Doom
Post by Bill Sloman
Post by john larkin
On Wed, 29 May 2024 17:12:21 -0000 (UTC), Cursitor Doom
Post by Cursitor Doom
Post by Bill Sloman
Yttrium iron garnet tuned oscillators were around back then, but
their 2GHz to 8GHz range was too high for me to count with the
integrated circuits around then - we had to go the Gigabit Logic's
GaAs parts to get to 800MHz, and that became the unique selling
point of the system.
YIG oscillators were quite the thing back in the day, but I'm
guessing they've been completely superseded by now to get to ever
higher frequencies. Seems we've gone from -
This misses Jan Panteltje's thread "Small magnetic tunable filter for
6G and beyond" which is about Yig being used today.
That article makes it seem like YIG is some revolutionary, new, emerging
technology!
Use of YIG filters as a replacement for varactor tuning could turn out to
be significant. 2022 Microwave Journal article:

<https://www.microwavejournal.com/articles/37980-reinventing-yig-
technology-for-microwave-filter-applications>
john larkin
2024-05-30 14:04:36 UTC
Permalink
Post by Glen Walpert
Post by Cursitor Doom
Post by Bill Sloman
Post by john larkin
On Wed, 29 May 2024 17:12:21 -0000 (UTC), Cursitor Doom
Post by Cursitor Doom
Post by Bill Sloman
Yttrium iron garnet tuned oscillators were around back then, but
their 2GHz to 8GHz range was too high for me to count with the
integrated circuits around then - we had to go the Gigabit Logic's
GaAs parts to get to 800MHz, and that became the unique selling
point of the system.
YIG oscillators were quite the thing back in the day, but I'm
guessing they've been completely superseded by now to get to ever
higher frequencies. Seems we've gone from -
This misses Jan Panteltje's thread "Small magnetic tunable filter for
6G and beyond" which is about Yig being used today.
That article makes it seem like YIG is some revolutionary, new, emerging
technology!
Use of YIG filters as a replacement for varactor tuning could turn out to
<https://www.microwavejournal.com/articles/37980-reinventing-yig-
technology-for-microwave-filter-applications>
The VIDA oscillators still look like giant expensive power hogs. They
don't specify modulation bandwidth on the data sheets that I see, but
it must be terrible.

One can't modulate a hundreds-of-mA electromagnet very fast.

An LC osc with a varicap is a more sensible VCO. Narrowband, one can
varicap a coaxial ceramic resonator, or a PCB ring oscillator, or
something. Cheap and fast.

Of course, it's inherently difficult to modulate a high-Q resonator
fast, even without an electromagnet in the way.
Bill Sloman
2024-05-30 16:50:29 UTC
Permalink
Post by john larkin
Post by Glen Walpert
Post by Cursitor Doom
Post by Bill Sloman
Post by john larkin
On Wed, 29 May 2024 17:12:21 -0000 (UTC), Cursitor Doom
Post by Cursitor Doom
Post by Bill Sloman
Yttrium iron garnet tuned oscillators were around back then, but
their 2GHz to 8GHz range was too high for me to count with the
integrated circuits around then - we had to go the Gigabit Logic's
GaAs parts to get to 800MHz, and that became the unique selling
point of the system.
YIG oscillators were quite the thing back in the day, but I'm
guessing they've been completely superseded by now to get to ever
higher frequencies. Seems we've gone from -
This misses Jan Panteltje's thread "Small magnetic tunable filter for
6G and beyond" which is about Yig being used today.
That article makes it seem like YIG is some revolutionary, new, emerging
technology!
Use of YIG filters as a replacement for varactor tuning could turn out to
<https://www.microwavejournal.com/articles/37980-reinventing-yig-
technology-for-microwave-filter-applications>
The VIDA oscillators still look like giant expensive power hogs. They
don't specify modulation bandwidth on the data sheets that I see, but
it must be terrible.
https://www.nature.com/articles/s41467-024-47822-3

makes quite a lot of fuss about them not being power hogs.
Post by john larkin
One can't modulate a hundreds-of-mA electromagnet very fast.
In fact they tweak quite a compact permanent magnet stack. How fast they
can do it isn't discussed (or at least if they did I didn't notice it).
Post by john larkin
An LC osc with a varicap is a more sensible VCO. Narrowband, one can
varicap a coaxial ceramic resonator, or a PCB ring oscillator, or
something. Cheap and fast.
Varicaps are horribly non-linear. Narrow-band is always easier than
wide-band, but the YIG tuning scheme is good for at least a factor of
two frequency range and once you've got that you can use counters to go
down from there until you run out of dividers
Post by john larkin
Of course, it's inherently difficult to modulate a high-Q resonator
fast, even without an electromagnet in the way.
You don't need an electromagnet to get the fields required. You may want
a non-conducting permanent magnet to proved the bulk of the field - or
it might be enough to split your magnetic path into lots of parallel
wire magnets insulated from one another. There are ferrite permanent
magnets which aren't all that electrically conductive.

This reads more as if you don't want it to work - it's the sort of
contribution that gets people chucked out of brain-storming sessions.
--
Bill Sloman, Sydney
Phil Hobbs
2024-05-30 21:46:20 UTC
Permalink
Post by john larkin
Post by Glen Walpert
Post by Cursitor Doom
Post by Bill Sloman
Post by john larkin
On Wed, 29 May 2024 17:12:21 -0000 (UTC), Cursitor Doom
Post by Cursitor Doom
Post by Bill Sloman
Yttrium iron garnet tuned oscillators were around back then, but
their 2GHz to 8GHz range was too high for me to count with the
integrated circuits around then - we had to go the Gigabit Logic's
GaAs parts to get to 800MHz, and that became the unique selling
point of the system.
YIG oscillators were quite the thing back in the day, but I'm
guessing they've been completely superseded by now to get to ever
higher frequencies. Seems we've gone from -
This misses Jan Panteltje's thread "Small magnetic tunable filter for
6G and beyond" which is about Yig being used today.
That article makes it seem like YIG is some revolutionary, new, emerging
technology!
Use of YIG filters as a replacement for varactor tuning could turn out to
<https://www.microwavejournal.com/articles/37980-reinventing-yig-
technology-for-microwave-filter-applications>
The VIDA oscillators still look like giant expensive power hogs. They
don't specify modulation bandwidth on the data sheets that I see, but
it must be terrible.
One can't modulate a hundreds-of-mA electromagnet very fast.
An LC osc with a varicap is a more sensible VCO. Narrowband, one can
varicap a coaxial ceramic resonator, or a PCB ring oscillator, or
something. Cheap and fast.
And far, far noisier than the best YIGs.
Post by john larkin
Of course, it's inherently difficult to modulate a high-Q resonator
fast, even without an electromagnet in the way.
It isn’t, actually, at least over a restricted range. If the resonator
obeys a differential equation, you can modulate its resonance much faster
than f_0/Q by changing L or C.

Resonators with significant time delay, such as a long piece of coax,
aren’t as friendly that way.

Cheers

Phil Hobbs
--
Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC /
Hobbs ElectroOptics Optics, Electro-optics, Photonics, Analog Electronics
john larkin
2024-05-30 21:50:07 UTC
Permalink
On Thu, 30 May 2024 21:46:20 -0000 (UTC), Phil Hobbs
Post by Phil Hobbs
Post by john larkin
Post by Glen Walpert
Post by Cursitor Doom
Post by Bill Sloman
Post by john larkin
On Wed, 29 May 2024 17:12:21 -0000 (UTC), Cursitor Doom
Post by Cursitor Doom
Post by Bill Sloman
Yttrium iron garnet tuned oscillators were around back then, but
their 2GHz to 8GHz range was too high for me to count with the
integrated circuits around then - we had to go the Gigabit Logic's
GaAs parts to get to 800MHz, and that became the unique selling
point of the system.
YIG oscillators were quite the thing back in the day, but I'm
guessing they've been completely superseded by now to get to ever
higher frequencies. Seems we've gone from -
This misses Jan Panteltje's thread "Small magnetic tunable filter for
6G and beyond" which is about Yig being used today.
That article makes it seem like YIG is some revolutionary, new, emerging
technology!
Use of YIG filters as a replacement for varactor tuning could turn out to
<https://www.microwavejournal.com/articles/37980-reinventing-yig-
technology-for-microwave-filter-applications>
The VIDA oscillators still look like giant expensive power hogs. They
don't specify modulation bandwidth on the data sheets that I see, but
it must be terrible.
One can't modulate a hundreds-of-mA electromagnet very fast.
An LC osc with a varicap is a more sensible VCO. Narrowband, one can
varicap a coaxial ceramic resonator, or a PCB ring oscillator, or
something. Cheap and fast.
And far, far noisier than the best YIGs.
Coaxial ceramic resonators have Qs in the thousands, and low tempcos.
Phil Hobbs
2024-05-31 00:04:47 UTC
Permalink
Post by john larkin
On Thu, 30 May 2024 21:46:20 -0000 (UTC), Phil Hobbs
Post by Phil Hobbs
Post by john larkin
Post by Glen Walpert
Post by Cursitor Doom
Post by Bill Sloman
Post by john larkin
On Wed, 29 May 2024 17:12:21 -0000 (UTC), Cursitor Doom
Post by Cursitor Doom
Post by Bill Sloman
Yttrium iron garnet tuned oscillators were around back then, but
their 2GHz to 8GHz range was too high for me to count with the
integrated circuits around then - we had to go the Gigabit Logic's
GaAs parts to get to 800MHz, and that became the unique selling
point of the system.
YIG oscillators were quite the thing back in the day, but I'm
guessing they've been completely superseded by now to get to ever
higher frequencies. Seems we've gone from -
This misses Jan Panteltje's thread "Small magnetic tunable filter for
6G and beyond" which is about Yig being used today.
That article makes it seem like YIG is some revolutionary, new, emerging
technology!
Use of YIG filters as a replacement for varactor tuning could turn out to
<https://www.microwavejournal.com/articles/37980-reinventing-yig-
technology-for-microwave-filter-applications>
The VIDA oscillators still look like giant expensive power hogs. They
don't specify modulation bandwidth on the data sheets that I see, but
it must be terrible.
One can't modulate a hundreds-of-mA electromagnet very fast.
An LC osc with a varicap is a more sensible VCO. Narrowband, one can
varicap a coaxial ceramic resonator, or a PCB ring oscillator, or
something. Cheap and fast.
And far, far noisier than the best YIGs.
Coaxial ceramic resonators have Qs in the thousands, and low tempcos.
If you can find one at the exact frequency you need. YIGs have a huge
tuning range.

IIRC you also said that they’re piezoelectric.

I’m not saying that YIG is the answer to everything, but for some things
it’s amazing and (AFAIK) unique.

Sure improves spectrum analyzers!

Cheers

Phil Hobbs
--
Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC /
Hobbs ElectroOptics Optics, Electro-optics, Photonics, Analog Electronics
john larkin
2024-05-31 10:40:28 UTC
Permalink
On Fri, 31 May 2024 00:04:47 -0000 (UTC), Phil Hobbs
Post by Phil Hobbs
Post by john larkin
On Thu, 30 May 2024 21:46:20 -0000 (UTC), Phil Hobbs
Post by Phil Hobbs
Post by john larkin
Post by Glen Walpert
Post by Cursitor Doom
Post by Bill Sloman
Post by john larkin
On Wed, 29 May 2024 17:12:21 -0000 (UTC), Cursitor Doom
Post by Cursitor Doom
Post by Bill Sloman
Yttrium iron garnet tuned oscillators were around back then, but
their 2GHz to 8GHz range was too high for me to count with the
integrated circuits around then - we had to go the Gigabit Logic's
GaAs parts to get to 800MHz, and that became the unique selling
point of the system.
YIG oscillators were quite the thing back in the day, but I'm
guessing they've been completely superseded by now to get to ever
higher frequencies. Seems we've gone from -
This misses Jan Panteltje's thread "Small magnetic tunable filter for
6G and beyond" which is about Yig being used today.
That article makes it seem like YIG is some revolutionary, new, emerging
technology!
Use of YIG filters as a replacement for varactor tuning could turn out to
<https://www.microwavejournal.com/articles/37980-reinventing-yig-
technology-for-microwave-filter-applications>
The VIDA oscillators still look like giant expensive power hogs. They
don't specify modulation bandwidth on the data sheets that I see, but
it must be terrible.
One can't modulate a hundreds-of-mA electromagnet very fast.
An LC osc with a varicap is a more sensible VCO. Narrowband, one can
varicap a coaxial ceramic resonator, or a PCB ring oscillator, or
something. Cheap and fast.
And far, far noisier than the best YIGs.
Coaxial ceramic resonators have Qs in the thousands, and low tempcos.
If you can find one at the exact frequency you need. YIGs have a huge
tuning range.
IIRC you also said that they’re piezoelectric.
The CCRs are high-K, usually shorted, transmission lines, not
piezoelectric. Prop delay is a tiny fraction of c. You can TDR them as
such. Z is usually in the 10 ohm ballpark.
Post by Phil Hobbs
I’m not saying that YIG is the answer to everything, but for some things
it’s amazing and (AFAIK) unique.
No argument, but they will always be big and expensive slow-tuning
power hogs, which is fine in a spectrum analyzer.

RF synthesizer chips are pretty amazing these days too. They make a
pretty good first LO too, but they are small and cheap.
Post by Phil Hobbs
Sure improves spectrum analyzers!
I wonder if the latest SAs use YIGs.
Post by Phil Hobbs
Cheers
Phil Hobbs
Bill Sloman
2024-05-31 11:24:33 UTC
Permalink
Post by john larkin
On Fri, 31 May 2024 00:04:47 -0000 (UTC), Phil Hobbs
Post by Phil Hobbs
Post by john larkin
Post by Phil Hobbs
Post by john larkin
Post by Glen Walpert
Post by Cursitor Doom
Post by Bill Sloman
Post by Cursitor Doom
Post by Bill Sloman
Yttrium iron garnet tuned oscillators were around back then, but
their 2GHz to 8GHz range was too high for me to count with the
integrated circuits around then - we had to go the Gigabit Logic's
GaAs parts to get to 800MHz, and that became the unique selling
point of the system.
YIG oscillators were quite the thing back in the day, but I'm
guessing they've been completely superseded by now to get to ever
higher frequencies. Seems we've gone from -
This misses Jan Panteltje's thread "Small magnetic tunable filter for
6G and beyond" which is about Yig being used today.
That article makes it seem like YIG is some revolutionary, new, emerging
technology!
Use of YIG filters as a replacement for varactor tuning could turn out to
<https://www.microwavejournal.com/articles/37980-reinventing-yig-
technology-for-microwave-filter-applications>
The VIDA oscillators still look like giant expensive power hogs. They
don't specify modulation bandwidth on the data sheets that I see, but
it must be terrible.
One can't modulate a hundreds-of-mA electromagnet very fast.
An LC osc with a varicap is a more sensible VCO. Narrowband, one can
varicap a coaxial ceramic resonator, or a PCB ring oscillator, or
something. Cheap and fast.
And far, far noisier than the best YIGs.
Coaxial ceramic resonators have Qs in the thousands, and low tempcos.
If you can find one at the exact frequency you need. YIGs have a huge
tuning range.
IIRC you also said that they’re piezoelectric.
The CCRs are high-K, usually shorted, transmission lines, not
piezoelectric. Prop delay is a tiny fraction of c. You can TDR them as
such. Z is usually in the 10 ohm ballpark.
Post by Phil Hobbs
I’m not saying that YIG is the answer to everything, but for some things
it’s amazing and (AFAIK) unique.
No argument, but they will always be big and expensive slow-tuning
power hogs, which is fine in a spectrum analyzer.
Except that they don't have to be, as

https://www.nature.com/articles/s41467-024-47822-3

pointed out. Modern lithography and surface mount assembly can let you
get away with a much smaller active device, and if you get the bulk of
your magnetic field from a permanent magnet, you don't need a lot of power.
Post by john larkin
RF synthesizer chips are pretty amazing these days too. They make a
pretty good first LO too, but they are small and cheap.
Not all that cheap, and there's quite a bit higher harmonic content to
filter out.
Post by john larkin
Post by Phil Hobbs
Sure improves spectrum analyzers!
I wonder if the latest SAs use YIGs.
Keysight's do.

https://docs.keysight.com/kkbopen/yig-spheres-the-gems-in-your-signal-analyzer-604584429.html
--
Bill Sloman, Sydney
Jeroen Belleman
2024-05-31 11:29:02 UTC
Permalink
Post by john larkin
On Fri, 31 May 2024 00:04:47 -0000 (UTC), Phil Hobbs
Post by Phil Hobbs
Post by john larkin
On Thu, 30 May 2024 21:46:20 -0000 (UTC), Phil Hobbs
Post by Phil Hobbs
Post by john larkin
Post by Glen Walpert
Post by Cursitor Doom
Post by Bill Sloman
Post by john larkin
On Wed, 29 May 2024 17:12:21 -0000 (UTC), Cursitor Doom
Post by Cursitor Doom
Post by Bill Sloman
Yttrium iron garnet tuned oscillators were around back then, but
their 2GHz to 8GHz range was too high for me to count with the
integrated circuits around then - we had to go the Gigabit Logic's
GaAs parts to get to 800MHz, and that became the unique selling
point of the system.
YIG oscillators were quite the thing back in the day, but I'm
guessing they've been completely superseded by now to get to ever
higher frequencies. Seems we've gone from -
This misses Jan Panteltje's thread "Small magnetic tunable filter for
6G and beyond" which is about Yig being used today.
That article makes it seem like YIG is some revolutionary, new, emerging
technology!
Use of YIG filters as a replacement for varactor tuning could turn out to
<https://www.microwavejournal.com/articles/37980-reinventing-yig-
technology-for-microwave-filter-applications>
The VIDA oscillators still look like giant expensive power hogs. They
don't specify modulation bandwidth on the data sheets that I see, but
it must be terrible.
One can't modulate a hundreds-of-mA electromagnet very fast.
An LC osc with a varicap is a more sensible VCO. Narrowband, one can
varicap a coaxial ceramic resonator, or a PCB ring oscillator, or
something. Cheap and fast.
And far, far noisier than the best YIGs.
Coaxial ceramic resonators have Qs in the thousands, and low tempcos.
If you can find one at the exact frequency you need. YIGs have a huge
tuning range.
IIRC you also said that they’re piezoelectric.
The CCRs are high-K, usually shorted, transmission lines, not
piezoelectric. Prop delay is a tiny fraction of c. You can TDR them as
such. Z is usually in the 10 ohm ballpark.
Post by Phil Hobbs
I’m not saying that YIG is the answer to everything, but for some things
it’s amazing and (AFAIK) unique.
No argument, but they will always be big and expensive slow-tuning
power hogs, which is fine in a spectrum analyzer.
RF synthesizer chips are pretty amazing these days too. They make a
pretty good first LO too, but they are small and cheap.
Post by Phil Hobbs
Sure improves spectrum analyzers!
I wonder if the latest SAs use YIGs.
Post by Phil Hobbs
Cheers
Phil Hobbs
I gather many spectrum analyzers these days mix successive
slices of the spectrum down to where an ADC can acquire the
whole slice, and the remaining processing is all software FTs.

No need for YIG oscillators, and the LO synthesizer needs
only coarse steps.

Jeroen Belleman
Phil Hobbs
2024-05-31 11:32:11 UTC
Permalink
Post by Jeroen Belleman
Post by john larkin
On Fri, 31 May 2024 00:04:47 -0000 (UTC), Phil Hobbs
Post by Phil Hobbs
Post by john larkin
On Thu, 30 May 2024 21:46:20 -0000 (UTC), Phil Hobbs
Post by Phil Hobbs
Post by john larkin
Post by Glen Walpert
Post by Cursitor Doom
Post by Bill Sloman
Post by john larkin
On Wed, 29 May 2024 17:12:21 -0000 (UTC), Cursitor Doom
Post by Cursitor Doom
Post by Bill Sloman
Yttrium iron garnet tuned oscillators were around back then, but
their 2GHz to 8GHz range was too high for me to count with the
integrated circuits around then - we had to go the Gigabit Logic's
GaAs parts to get to 800MHz, and that became the unique selling
point of the system.
YIG oscillators were quite the thing back in the day, but I'm
guessing they've been completely superseded by now to get to ever
higher frequencies. Seems we've gone from -
This misses Jan Panteltje's thread "Small magnetic tunable filter for
6G and beyond" which is about Yig being used today.
That article makes it seem like YIG is some revolutionary, new, emerging
technology!
Use of YIG filters as a replacement for varactor tuning could turn out to
<https://www.microwavejournal.com/articles/37980-reinventing-yig-
technology-for-microwave-filter-applications>
The VIDA oscillators still look like giant expensive power hogs. They
don't specify modulation bandwidth on the data sheets that I see, but
it must be terrible.
One can't modulate a hundreds-of-mA electromagnet very fast.
An LC osc with a varicap is a more sensible VCO. Narrowband, one can
varicap a coaxial ceramic resonator, or a PCB ring oscillator, or
something. Cheap and fast.
And far, far noisier than the best YIGs.
Coaxial ceramic resonators have Qs in the thousands, and low tempcos.
If you can find one at the exact frequency you need. YIGs have a huge
tuning range.
IIRC you also said that they’re piezoelectric.
The CCRs are high-K, usually shorted, transmission lines, not
piezoelectric. Prop delay is a tiny fraction of c. You can TDR them as
such. Z is usually in the 10 ohm ballpark.
Post by Phil Hobbs
I’m not saying that YIG is the answer to everything, but for some things
it’s amazing and (AFAIK) unique.
No argument, but they will always be big and expensive slow-tuning
power hogs, which is fine in a spectrum analyzer.
RF synthesizer chips are pretty amazing these days too. They make a
pretty good first LO too, but they are small and cheap.
Post by Phil Hobbs
Sure improves spectrum analyzers!
I wonder if the latest SAs use YIGs.
Post by Phil Hobbs
Cheers
Phil Hobbs
I gather many spectrum analyzers these days mix successive
slices of the spectrum down to where an ADC can acquire the
whole slice, and the remaining processing is all software FTs.
No need for YIG oscillators, and the LO synthesizer needs
only coarse steps.
Jeroen Belleman
Sure, that’s the software-defined radio (SDR) approach. Works great for
many things, but good close-in phase noise is not one of them.

Cheers

Phil Hobbs
--
Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC /
Hobbs ElectroOptics Optics, Electro-optics, Photonics, Analog Electronics
john larkin
2024-05-31 11:40:05 UTC
Permalink
On Fri, 31 May 2024 13:29:02 +0200, Jeroen Belleman
Post by Jeroen Belleman
Post by john larkin
On Fri, 31 May 2024 00:04:47 -0000 (UTC), Phil Hobbs
Post by Phil Hobbs
Post by john larkin
On Thu, 30 May 2024 21:46:20 -0000 (UTC), Phil Hobbs
Post by Phil Hobbs
Post by john larkin
Post by Glen Walpert
Post by Cursitor Doom
Post by Bill Sloman
Post by john larkin
On Wed, 29 May 2024 17:12:21 -0000 (UTC), Cursitor Doom
Post by Cursitor Doom
Post by Bill Sloman
Yttrium iron garnet tuned oscillators were around back then, but
their 2GHz to 8GHz range was too high for me to count with the
integrated circuits around then - we had to go the Gigabit Logic's
GaAs parts to get to 800MHz, and that became the unique selling
point of the system.
YIG oscillators were quite the thing back in the day, but I'm
guessing they've been completely superseded by now to get to ever
higher frequencies. Seems we've gone from -
This misses Jan Panteltje's thread "Small magnetic tunable filter for
6G and beyond" which is about Yig being used today.
That article makes it seem like YIG is some revolutionary, new, emerging
technology!
Use of YIG filters as a replacement for varactor tuning could turn out to
<https://www.microwavejournal.com/articles/37980-reinventing-yig-
technology-for-microwave-filter-applications>
The VIDA oscillators still look like giant expensive power hogs. They
don't specify modulation bandwidth on the data sheets that I see, but
it must be terrible.
One can't modulate a hundreds-of-mA electromagnet very fast.
An LC osc with a varicap is a more sensible VCO. Narrowband, one can
varicap a coaxial ceramic resonator, or a PCB ring oscillator, or
something. Cheap and fast.
And far, far noisier than the best YIGs.
Coaxial ceramic resonators have Qs in the thousands, and low tempcos.
If you can find one at the exact frequency you need. YIGs have a huge
tuning range.
IIRC you also said that they’re piezoelectric.
The CCRs are high-K, usually shorted, transmission lines, not
piezoelectric. Prop delay is a tiny fraction of c. You can TDR them as
such. Z is usually in the 10 ohm ballpark.
Post by Phil Hobbs
I’m not saying that YIG is the answer to everything, but for some things
it’s amazing and (AFAIK) unique.
No argument, but they will always be big and expensive slow-tuning
power hogs, which is fine in a spectrum analyzer.
RF synthesizer chips are pretty amazing these days too. They make a
pretty good first LO too, but they are small and cheap.
Post by Phil Hobbs
Sure improves spectrum analyzers!
I wonder if the latest SAs use YIGs.
Post by Phil Hobbs
Cheers
Phil Hobbs
I gather many spectrum analyzers these days mix successive
slices of the spectrum down to where an ADC can acquire the
whole slice, and the remaining processing is all software FTs.
No need for YIG oscillators, and the LO synthesizer needs
only coarse steps.
Jeroen Belleman
Yes, digital IF.

The price of a several-GHZ sa has dropped by over 10:1 in the last 20
years, mostly from using a lot of digital stuff.

You can get an impressive 8 GHz RF synth chip for about $5 now.

Bill Sloman
2024-05-30 12:50:09 UTC
Permalink
Post by Cursitor Doom
Post by Bill Sloman
Post by john larkin
On Wed, 29 May 2024 17:12:21 -0000 (UTC), Cursitor Doom
Post by Cursitor Doom
Post by Bill Sloman
Yttrium iron garnet tuned oscillators were around back then, but
their 2GHz to 8GHz range was too high for me to count with the
integrated circuits around then - we had to go the Gigabit Logic's
GaAs parts to get to 800MHz, and that became the unique selling point
of the system.
YIG oscillators were quite the thing back in the day, but I'm guessing
they've been completely superseded by now to get to ever higher
frequencies. Seems we've gone from -
This misses Jan Panteltje's thread "Small magnetic tunable filter for 6G
and beyond" which is about Yig being used today.
That article makes it seem like YIG is some revolutionary, new, emerging
technology!
Of course it does. University researchers always want to create that
impression.

https://www.nature.com/articles/s41467-024-47822-3

does emphasis how their technique differs other's peoples schemes to
exploit an effect which has been around for quite a while. The idea of
electrically thumping and Al-Ni-Co permanent magnet to get it to deliver
precisely the static magnetic field you for as long as you want it is
neat, but perhaps more problematic than the authors admit.

They may need to add a Hall plate to their stack to keep track of the
actual magnetic field where it matters.
--
Bill Sloman, Sydney
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