Path: ...!eternal-september.org!feeder3.eternal-september.org!news.eternal-september.org!.POSTED!not-for-mail From: Bill Sloman Newsgroups: sci.electronics.design Subject: Re: Yttrium iron garnet Date: Fri, 31 May 2024 21:24:33 +1000 Organization: A noiseless patient Spider Lines: 90 Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Injection-Date: Fri, 31 May 2024 13:24:48 +0200 (CEST) Injection-Info: dont-email.me; posting-host="260f431e2b69ba4892176057e957978a"; logging-data="2329718"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX18NGwhnPs8BRrV5X0iMp++TgVJdOKTPQ3Q=" User-Agent: Mozilla Thunderbird Cancel-Lock: sha1:ZxAQosu5hr5T0Nhbt5Kcf+/tK6k= In-Reply-To: Content-Language: en-US Bytes: 5218 On 31/05/2024 8:40 pm, john larkin wrote: > On Fri, 31 May 2024 00:04:47 -0000 (UTC), Phil Hobbs > wrote: > >> john larkin wrote: >>> On Thu, 30 May 2024 21:46:20 -0000 (UTC), Phil Hobbs wrote: >>>> john larkin wrote: >>>>> On Thu, 30 May 2024 11:03:19 GMT, Glen Walpert wrote: >>>>>> On Thu, 30 May 2024 09:14:58 -0000 (UTC), Cursitor Doom wrote: >>>>>>> On Thu, 30 May 2024 15:45:21 +1000, Bill Sloman wrote: >>>>>>>> On 30/05/2024 3:37 am, john larkin wrote: >>>>>>>>> On Wed, 29 May 2024 17:12:21 -0000 (UTC), Cursitor Doom wrote: >>>>>>>>>> On Wed, 29 May 2024 13:52:34 +1000, Bill Sloman wrote: >>>>>>>>>> >>>>>>>>>>> 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 guessing they've been completely superseded by now to get to ever 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: >>>>>> >>>>>> >>>>> 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. > >> 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. > 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. >> 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