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
    Clear explanations instead of links are preferred. Thank you.
  2. KL7AJ

    Senior Member

    Nov 4, 2008

    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.

  3. DickCappels


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