Path: ...!Xl.tags.giganews.com!local-1.nntp.ord.giganews.com!nntp.supernews.com!news.supernews.com.POSTED!not-for-mail NNTP-Posting-Date: Fri, 31 May 2024 10:40:28 +0000 From: john larkin Newsgroups: sci.electronics.design Subject: Re: Yttrium iron garnet Date: Fri, 31 May 2024 03:40:28 -0700 Message-ID: References: User-Agent: ForteAgent/8.00.32.1272 MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8bit Lines: 87 X-Trace: sv3-5RrbWcajk4qQ3HPwvMY5E9ta54xb2H82BzA1nQV7K42OiwUfgkwEVTQZCMWHMPnBGD05VjarX9mTHHT!1Lf8AG/g1BPeDmwuBHDn0frjZXJ9g9v0qAhrt5D/2SowKxnlrRcdovKFqzzKoMWzXQfSAeg3RnYj!koUKuA== X-Complaints-To: www.supernews.com/docs/abuse.html X-DMCA-Complaints-To: www.supernews.com/docs/dmca.html X-Abuse-and-DMCA-Info: Please be sure to forward a copy of ALL headers X-Abuse-and-DMCA-Info: Otherwise we will be unable to process your complaint properly X-Postfilter: 1.3.40 Bytes: 4605 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 guessing they've been completely superseded by now to get to ever 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. RF synthesizer chips are pretty amazing these days too. They make a pretty good first LO too, but they are small and cheap. > >Sure improves spectrum analyzers! I wonder if the latest SAs use YIGs. > >Cheers > >Phil Hobbs