Path: ...!weretis.net!feeder9.news.weretis.net!feeder8.news.weretis.net!eternal-september.org!feeder3.eternal-september.org!news.eternal-september.org!.POSTED!not-for-mail From: Phil Hobbs Newsgroups: sci.electronics.design Subject: Re: Small magnetic tunable filter for 6G and beyond Date: Mon, 27 May 2024 12:59:31 -0000 (UTC) Organization: A noiseless patient Spider Lines: 61 Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Injection-Date: Mon, 27 May 2024 14:59:31 +0200 (CEST) Injection-Info: dont-email.me; posting-host="79bbfbff0e05e8061551fc433504c7e1"; logging-data="52025"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX1/Nbc9OITr4n48Yixdbze5o" User-Agent: NewsTap/5.5 (iPhone/iPod Touch) Cancel-Lock: sha1:hPiz+7crjsz5121tXlzF1EDUbDU= sha1:2W43UUhmtSmEkNhe0/7wpdBHsuU= Bytes: 3635 Phil Hobbs wrote: > Jeroen Belleman wrote: >> On 5/27/24 07:08, Jan Panteltje wrote: >>> To 6G and beyond: Engineers unlock the next generation of wireless communications: >>> https://www.sciencedaily.com/releases/2024/05/240524114938.htm >>> Source: >>> University of Pennsylvania School of Engineering and Applied Science >>> Summary: >>> Engineers have developed a new tool that could unlock 6G and the next >>> generation of wireless networks: an adjustable filter that can >>> successfully prevent interference in high-frequency bands of the >>> electromagnetic spectrum. >>> partial quote: >>> What makes the filter adjustable is a unique material, "yttrium iron garnet" (YIG), >>> a blend of yttrium, a rare earth metal, along with iron and oxygen. >>> "What's special about YIG is that it propagates a magnetic spin wave," says Olsson, >>> referring to the type of wave created in magnetic materials when >>> electrons spin in a synchronized fashion. >>> When exposed to a magnetic field, the magnetic spin wave generated by >>> YIG changes frequency. >>> "By adjusting the magnetic field," says Xingyu Du, a doctoral student in >>> Olsson's lab and the first author of the paper, >>> "the YIG filter achieves continuous frequency tuning across an extremely >>> broad frequency band." >>> As a result, the new filter can be tuned to any frequency between 3.4 GHz and 11.1 GHz, >>> which covers much of the new territory the FCC has opened up in the FR3 band. >>> >> >> YIG filter and resonators have always been a bit exotic. Maybe this >> will make them common-place. And more compact, hopefully! The YIG >> was tiny, sure, but the magnet wasn't. >> >> Jeroen Belleman >> > > YIG-tuned VFOs are the champs for low close-in phase noise. My HP 8566B’s > noise floor at 1kHz offset is a good 30 dB better than any SDR-style analyzer. > > If they manage to get them down to Digikey-level practicality without > screwing that up, it would be huge. > > I wonder if you could use a mag amp sort of structure, with a rare earth > magnet biasing some cleverly designed bits of saturable ferrite, plus some > small coils changing the effective gap in the magnetic circuit. > > Fun to think about. > > Cheers > > Phil Hobbs > -- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC / Hobbs ElectroOptics Optics, Electro-optics, Photonics, Analog Electronics