big yig sphere? - Page 1
Forum section: electronics / rf-microwave

author: coppercone2
author_rank: Super Contributor
timestamp: October 18, 2024, 12:02:30 pm
content: I watched that ball of silicon that may have replaced the platinium kilogram and I wondered, what is the largest YIG RF device ever made?If you just got a big YIG sphere, could it make a intrinsically high power oscillator?If it was not hard to make or expensive, what would we be doing with YIG spheres the size of baseballs or larger?for reference,

author: RoV
author_rank: Regular Contributor
timestamp: October 18, 2024, 03:30:14 pm
content: It would be very very difficult to put it in a high intensity and uniform magnetic field. And would consume a lot of power.

author: RoV
author_rank: Regular Contributor
timestamp: October 18, 2024, 03:37:41 pm
content: Besides, if excited with a turn of wire, it'd have a large series inductance that would limit useful frequency.I don't remember if there is a relationship between frequency and diameter, or if multiple modes are subject to arise above a certain frequency.

author: coppercone2
author_rank: Super Contributor
timestamp: October 18, 2024, 03:47:22 pm
content: So it sounds like it needs some kind of magnetic field coupler to be invented for itI guess it would be a super conductor for spheres of unusual size

author: Kleinstein
author_rank: Super Contributor
timestamp: October 18, 2024, 06:35:30 pm
content: With a larger size to main point is a lower frequency. There is relatively little need for lower frequencies - in many cases it is more about extending the BW to higher frequencies.So little need for an increasingly more expensive part. It would be one a few uses for a high Q tunable filter at moderate frequencies. For just an oscillator there is the possibility to use a divider or mixer to get to lower frequencies.The magnetic field would not be that difficult - electromagents tend to get better when larger. It still needs more power for a larger volume but the power consumption is not going up that fast as one may expect.

author: coppercone2
author_rank: Super Contributor
timestamp: October 18, 2024, 07:44:22 pm
content: would it have more output power ?i thought maybe they might form somewhere naturally, like under water on a weird planet (like manganese nodules). Or some kind of weird life form that makes them like a pearl, or a crystaline growth (instead of square galina crystals)somewhere in the vastness of the universe it might be easyI thought maybe it could be a long lasting deep space beacon circuit (buoy)

author: Kleinstein
author_rank: Super Contributor
timestamp: October 18, 2024, 09:36:30 pm
content: A larger sphere may allow to use more power. However the power may not be that limited anyway. Usually the dielectric strength is pretty high and even a small sphere could support quite some voltage before really reaching a limitation from the sphere.The special thing about the YIG resonantors is that one can tune them over a relatively large range (much more than with a crystal) and still get a pretty good quality factor (better than with LC oscillators with varicaps). They are not good for a stable oscillator like a quarz crystal, as they are tunable via the magnetic field.

author: coppercone2
author_rank: Super Contributor
timestamp: October 23, 2024, 04:02:05 am
content: I wonder if there might be a planet that is a giant yig ball, maybe in orbit around a magnastar