What's the function of the dielectric resonator in a dielectric resonator oscillator?

Discussion in 'Wireless & RF Design' started by KLoong, May 5, 2012.

  1. KLoong

    Thread Starter New Member

    Mar 4, 2011
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    Clear explanations instead of links are preferred. Thank you.
     
  2. KL7AJ

    AAC Fanatic!

    Nov 4, 2008
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    287
    Yikes!

    This is s tough one....I don't even think the guy who invented it understands it!

    But here's a thoroughly inadequate explanation, for whatever it's worth.

    A dielectric resonator is functionally similar to a piezoelectric crystal, except the resonant frequency is determined not by physical vibration on the large scale, but rather on the MOLECULAR scale. The main characteristic of a dielectric is that it slows down radio propagation, as compared to air or in a vacuum. The most IMPORTANT phenomenon is what happens at the BOUNDARY between the dielectric and the air...there is a sudden change of velocity which results in a total reflection at the surface back INTO the chunk of dielectric material. Because of the slow velocity of propagation, the dielectric slug can be made very small, compared to a similar "cavity resonator"

    R.F. input into and out of the resonator is generally by means of capacitive coupling, just as in a piezo crystal.

    Hope this helps a little. There are entire PhD theses on how these things work, if you're really interested.

    Eric
     
  3. DickCappels

    Moderator

    Aug 21, 2008
    2,653
    632
    Not so hard: It resonates, and that makes it suitable for filtering.
     
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