Path: ...!news.mixmin.net!eternal-september.org!feeder3.eternal-september.org!news.eternal-september.org!.POSTED!not-for-mail From: Bill Sloman Newsgroups: sci.electronics.design Subject: Re: Small magnetic tunable filter for 6G and beyond Date: Thu, 30 May 2024 00:13:17 +1000 Organization: A noiseless patient Spider Lines: 53 Message-ID: References: <4pi95jln0ibs3afptjm6gn319uh90ub6dn@4ax.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Injection-Date: Wed, 29 May 2024 16:13:24 +0200 (CEST) Injection-Info: dont-email.me; posting-host="aadcd11aabf832e072bbfc3a4de4d04c"; logging-data="1243307"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX1+yDA3kWwT+9R0jU5y5ZmMI6KVfcH+9YrE=" User-Agent: Mozilla Thunderbird Cancel-Lock: sha1:zS3xiFWqoF9hg3jOtP2AxMDC984= In-Reply-To: <4pi95jln0ibs3afptjm6gn319uh90ub6dn@4ax.com> Content-Language: en-US Bytes: 3853 On 28/05/2024 4:06 am, john larkin wrote: > On Mon, 27 May 2024 13:27:02 -0400, Joe Gwinn > wrote: > >> On Mon, 27 May 2024 05:08:40 GMT, 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. >> >> As with many breathless announcements of breakthroughs, this may not >> fare well in reality, for all the reasons mentioned up thread. But >> anyway, here is the full announcement: >> >> . >> >> The item about LightSquared is amusingly off-mark: The problem with >> LightSquared was that their proposed ground-based transmissions were >> far too strong, and threatened to overwhelm existing GPS receivers, in >> particular those in safety-of-flight involved GPS receivers. Inventing >> a fancy new filter won't help any more than boring old filter >> technologies, as it's the GPS receivers would need to be updated and >> recertified, which is a very big deal. >> >> I haven't looked, but I bet there is an arXive paper on the yig filter >> details. >> >> Joe Gwinn > > Does satellite nevigation need a low-Q tunable bandpass filter? There > are great SAW-type resonators around with better filtering, no magnets > required. But they aren't tunable. -- Bill Sloman, Sydney