Path: ...!local-4.nntp.ord.giganews.com!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 11:40:05 +0000 From: john larkin Newsgroups: sci.electronics.design Subject: Re: Yttrium iron garnet Date: Fri, 31 May 2024 04:40:05 -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: 108 X-Trace: sv3-mjKWzMxwLYh5tAn5nP8vMk2hayIrNZxtr0w9FKocxDbwWGH+bOHzjKGTuJfsSO0HWop/LoG2xwbxRmM!tKwbNzbnZbDmjz1s0lCo33MLL0xdlCT6nKYXLFjobAN5ekwpSKoPd/JOLZsskCEE9FMi06x3FvRY!/lzqzw== 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: 5491 On Fri, 31 May 2024 13:29:02 +0200, Jeroen Belleman wrote: >On 5/31/24 12:40, 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 guessing they've been completely superseded by now to get to ever 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. >> >> 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 > >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.