Cool visual patterns: https://dl.dropboxusercontent.com/u/53724080/Circuits/Oscillators/Coupled_Resonators.jpg The waveforms decay, which must be some Spice setting. Ideal resonators wouldn't lose energy. Gear integration is much worse than trap. -- John Larkin Highland Technology, Inc picosecond timing laser drivers and controllers jlarkin att highlandtechnology dott com http://www.highlandtechnology.com
coupled resonators
Started by ●January 31, 2015
Reply by ●January 31, 20152015-01-31
On Sat, 31 Jan 2015 09:46:55 -0800, John Larkin <jlarkin@highlandtechnology.com> wrote:> > >Cool visual patterns: > >https://dl.dropboxusercontent.com/u/53724080/Circuits/Oscillators/Coupled_Resonators.jpg > >The waveforms decay, which must be some Spice setting. Ideal >resonators wouldn't lose energy. Gear integration is much worse than >trap.LTspice has a default of a series R for each inductor. ...Jim Thompson -- | James E.Thompson | mens | | Analog Innovations | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | San Tan Valley, AZ 85142 Skype: skypeanalog | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at http://www.analog-innovations.com | 1962 | I love to cook with wine. Sometimes I even put it in the food.
Reply by ●January 31, 20152015-01-31
If you do an AC sweep, you'll see either a nice sharp peak, or two individual peaks. How much depends on the coupling between resonators and their individual Qs. The positioning of the peaks depends more on the coupling coefficient than the tuning of the individual resonators, but the balance between peaks does depend upon tuning. With ideal SPICE components (whether you've checked that or not; LTSpice lies about its schematics) and no losses, you can expect every grouping of resonators to have two very sharp peaks. With no coupling from or to anything, it's not very practical, of course. The necessary time-domain function arising from such a system is, of course, a complementary pair of sine-enveloped decaying exponentials, with the period of that envelope being the difference between peaks. Tim -- Seven Transistor Labs Electrical Engineering Consultation Website: http://seventransistorlabs.com "John Larkin" <jlarkin@highlandtechnology.com> wrote in message news:5o4qcatachr67e1paofbck23f6jsrsej26@4ax.com...> > > Cool visual patterns: > > https://dl.dropboxusercontent.com/u/53724080/Circuits/Oscillators/Coupled_Resonators.jpg > > The waveforms decay, which must be some Spice setting. Ideal > resonators wouldn't lose energy. Gear integration is much worse than > trap. > > > -- > > John Larkin Highland Technology, Inc > picosecond timing laser drivers and controllers > > jlarkin att highlandtechnology dott com > http://www.highlandtechnology.com >
Reply by ●January 31, 20152015-01-31
On a sunny day (Sat, 31 Jan 2015 12:07:23 -0600) it happened "Tim Williams" <tmoranwms@charter.net> wrote in <maj5j5$jt9$1@dont-email.me>:>If you do an AC sweep, you'll see either a nice sharp peak, or two >individual peaks. How much depends on the coupling between resonators and >their individual Qs. The positioning of the peaks depends more on the >coupling coefficient than the tuning of the individual resonators, but the >balance between peaks does depend upon tuning.Right, we used to call that a bandfilter :-)
Reply by ●January 31, 20152015-01-31
On a sunny day (Sat, 31 Jan 2015 19:07:30 GMT) it happened Jan Panteltje <pNaonStpealmtje@yahoo.com> wrote in <maj940$qek$1@news.albasani.net>:>On a sunny day (Sat, 31 Jan 2015 12:07:23 -0600) it happened "Tim Williams" ><tmoranwms@charter.net> wrote in <maj5j5$jt9$1@dont-email.me>: > >>If you do an AC sweep, you'll see either a nice sharp peak, or two >>individual peaks. How much depends on the coupling between resonators and >>their individual Qs. The positioning of the peaks depends more on the >>coupling coefficient than the tuning of the individual resonators, but the >>balance between peaks does depend upon tuning. > >Right, we used to call that a bandfilter :-)PS the Dutxh wikipedia shows it better than the English one, with a picture of the peaks versus coupling you describe: http://nl.wikipedia.org/wiki/Bandfilter http://commons.wikimedia.org/wiki/File:Bandfilter.png
Reply by ●January 31, 20152015-01-31
If you want more peaks (and sharper skirts), add more resonators in the chain; or if you want notches, add resonators on the side (or couple between odd ones). This is a good page, http://www.eee.bham.ac.uk/edt/filter/FilterDesignPage.html unfortunately with Java being so useless these days, it's a pain to add the exception to make the applet work. Back in the day of course, analog TV had nice broad IF (usually around 45MHz, with a 6MHz span), often called "stagger tuned", but if they were at all smart, they were actually doing this (overcoupled resonators). There are some lovely examples of cavity and coaxial type resonators in cell tower equipment, say for FDM/multiplexing channels in the 900MHz range, and others. Any commercial radio equipment, really; anywhere the stuff up on the tower is more important (limited space for wideband antennas; limited access due to, well, yeah). Tim -- Seven Transistor Labs Electrical Engineering Consultation Website: http://seventransistorlabs.com "Jan Panteltje" <pNaonStpealmtje@yahoo.com> wrote in message news:maj9g6$r4h$1@news.albasani.net...> On a sunny day (Sat, 31 Jan 2015 19:07:30 GMT) it happened Jan Panteltje > <pNaonStpealmtje@yahoo.com> wrote in <maj940$qek$1@news.albasani.net>: > >>On a sunny day (Sat, 31 Jan 2015 12:07:23 -0600) it happened "Tim >>Williams" >><tmoranwms@charter.net> wrote in <maj5j5$jt9$1@dont-email.me>: >> >>>If you do an AC sweep, you'll see either a nice sharp peak, or two >>>individual peaks. How much depends on the coupling between resonators >>>and >>>their individual Qs. The positioning of the peaks depends more on the >>>coupling coefficient than the tuning of the individual resonators, but >>>the >>>balance between peaks does depend upon tuning. >> >>Right, we used to call that a bandfilter :-) > > PS > the Dutxh wikipedia shows it better than the English one, > with a picture of the peaks versus coupling you describe: > http://nl.wikipedia.org/wiki/Bandfilter > http://commons.wikimedia.org/wiki/File:Bandfilter.png >
Reply by ●January 31, 20152015-01-31
On a sunny day (Sat, 31 Jan 2015 13:40:30 -0600) it happened "Tim Williams" <tmoranwms@charter.net> wrote in <majb2b$ati$1@dont-email.me>:>If you want more peaks (and sharper skirts), add more resonators in the >chain; or if you want notches, add resonators on the side (or couple between >odd ones). > >This is a good page, >http://www.eee.bham.ac.uk/edt/filter/FilterDesignPage.html >unfortunately with Java being so useless these days, it's a pain to add the >exception to make the applet work.Got it working and display the TV IF curve. I designed the whole thing in the sixties, VHF tuner, 38 MHz IF, and 5.5 MHz FM demodulator (audio was 5.5 MHz FM inter-carrier here). H and V deflection 90 degrees, I also wound the HV transformer. Transistor TV! Used staggered tuning. I spend days calculating that H output transformer, with all I had learned... until finally it hit me: the DY type HV rectifier tubes ran on about 1.4 V from a ONE turn loop on all TVs I came across. so the transformer HAD to be 1. something volt per turn. :-) The H deflection coil was 440 Vpp I think, that only left the choice of ferrite, everything else just fell into place. The ferrite was easy as there were plenty of old HV transformers around... Primary 12V DC, and factor 4.5 or so peak on transistor switch off, say 70 V (more would kill the output transistor anyways), I think I can still do it without any calculation. Using just turns ratio, Q for the IF coils.>Back in the day of course, analog TV had nice broad IF (usually around >45MHz, with a 6MHz span), often called "stagger tuned", but if they were at >all smart, they were actually doing this (overcoupled resonators). > >There are some lovely examples of cavity and coaxial type resonators in cell >tower equipment, say for FDM/multiplexing channels in the 900MHz range, and >others. Any commercial radio equipment, really; anywhere the stuff up on >the tower is more important (limited space for wideband antennas; limited >access due to, well, yeah). >I have some nice RF attenuators in that superconducting cellphone filter I have, need to get that out some time and use it for testing, adjust1 and adjust2: http://panteltje.com/pub/super_filter/super_filter_connection_panel_img_2522.jpg The later analog TVs had SAW filters, made things a lot easier and cheaper. I once had to 'wobble' a TV IF to fix the curve, not so easy, takes a lot of time.
Reply by ●February 1, 20152015-02-01
In classical physics, search "line splitting" of coupled oscillators. It's the chassical version of QM's Pauli Exclusion principle, where two oscillators aren't allowed to be in the same state (have the same freq.) Note that as oscillations "slosh" between the resonators, the sloshing period is the same as the separation between peaks in the frequency domain. Make a big square array of resonators, and you've got a 2D crystal, and so much line-splitting that we end up with an "energy band" which is actually a large number of closely-spaced peaks. Hmmm, if we could plot the absolute value amplitude of every oscillator as a raster, then slam single elements (or groups) with transient spikes, what's that look like? For low coupling, it's thermal vibrations in solids. With high coupling it's just a patch of 2D waveguide with 2D waves bouncing around inside. Make a low-coupling "wave tank" where the "liquid' only passes slowly-moving oscillations along, rather than propagating waves.
Reply by ●February 1, 20152015-02-01
Reply by ●February 1, 20152015-02-01
That's not what the Pauli principle states, and it only applies to fermions anyway. Splitting of coupled quantum oscillators is what gives rise to the band structure of solids. Photons and other bosons don't behave the same way. (That's why there are lasers, among other things.) Besides IF transformers, two coupled classical modes make directional couplers possible. The math is simple and quite pretty. Cheers Phil Hobbs
