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| From | Tauno Voipio <tauno.voipio@notused.fi.invalid> |
| Newsgroups | sci.electronics.design |
| Subject | Re: Diode laser FM/AM modulation |
| Date | Fri, 10 Feb 2017 15:04:58 +0200 |
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On 9.2.17 19:39, George Herold wrote: > > Hmm can I ask a silly radio question. If I've got > (say) 50% AM, modulation index = 0.5, how big are the side bands compared > to the central carrier? (I guess I should be able to go look that up somewhere.) > (Or measure it myself) > > I could then go measure the AM MI for the laser and get some number. > > George H. There's no such thing as modulation index in AM. MI belongs to angle modulation (PM, FM). An AM signal modulated with a single sine wave is AM(t) = A(1 + M cos(omega_m t)) cos(omega_c t), where A = carrier amplitude M = modulation depth (0 .. 1) omega_m = modulation signal angle frequency omega_c = carrier signal angle frequency t = time. The expansion of the expression and cranking out the sideband signals from the cos(omega_m t) cos(omega_c t) is left as homework. -- -TV
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Diode laser FM/AM modulation George Herold <gherold@teachspin.com> - 2017-02-09 06:26 -0800
Re: Diode laser FM/AM modulation George Herold <gherold@teachspin.com> - 2017-02-09 07:22 -0800
Re: Diode laser FM/AM modulation Tim Wescott <tim@seemywebsite.com> - 2017-02-09 10:55 -0600
Re: Diode laser FM/AM modulation pcdhobbs@gmail.com - 2017-02-09 09:23 -0800
Re: Diode laser FM/AM modulation Tim Wescott <seemywebsite@myfooter.really> - 2017-02-09 12:06 -0600
Re: Diode laser FM/AM modulation Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2017-02-09 14:11 -0500
Re: Diode laser FM/AM modulation George Herold <gherold@teachspin.com> - 2017-02-09 12:33 -0800
Re: Diode laser FM/AM modulation George Herold <gherold@teachspin.com> - 2017-02-09 09:39 -0800
Re: Diode laser FM/AM modulation Tauno Voipio <tauno.voipio@notused.fi.invalid> - 2017-02-10 15:04 +0200
Re: Diode laser FM/AM modulation George Herold <gherold@teachspin.com> - 2017-02-10 06:24 -0800
Re: Diode laser FM/AM modulation Tauno Voipio <tauno.voipio@notused.fi.invalid> - 2017-02-10 17:36 +0200
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