Q Factor of Resonant Cavities
Basic Definition
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(1) |
In complex case (see examples in textbooks)
Since Ploss comes form W
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(2) |
Calculating from complex resonance Frequency
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Definition 1 (Correct)
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Definition 2 (Incorrect)
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(5) |
Arguments for using Definition 1
- Collin always uses the right frequency
- Gardiole [1] always uses definition1.
- IEEE papers [2], [3], and [5] use Definition 1.
Example R,L,C Circuit
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(6) |
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(7) |
Definition 1 (Correct)
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(8) |
Definition 2 (Incorrect)
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(9) |
Example Cube Resonator
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(10) |
Definition 1 (Correct)
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(11) |
Definition 2 (Incorrect)
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(12) |
- Both definitions give almost the same answer at low losses
- Definition 2 gives nonphysical values at high losses, so Definition 1 is the correct one