Design and Miniaturization of Loop Filter with Harmonic Suppression
| Autor: | WEN-LUNG HUANG, 黃文龍 |
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| Rok vydání: | 2008 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 96 This article utilized a loop resonator as a base for designing and realizing a band-pass filter. A quarter-wavelength open stub was then incorporated to suppress the second and third harmonics. The signal between the feed and resonator was enhanced by coupling feed and therefore can improve the insertion loss. The transmission zero for the electric and magnetic coupling in the lower and upper stopbands in the filter was implemented by a narrow coupling gap and connected via the ground to improve the signal-to-noise ratio (S/N ratio ) of the complete circuit. The proposed methodology is different from the cross couple technique but can be implemented to achieve the same performance. It also has the additional advantage of effectively reducing the circuit size. The original prototype of the original circuit is a resonator based on one wavelength structure and is slightly larger compared with the other structures. We therefore utilize a folding loop circuit to achieve miniaturization. The circuit size reduction is about 30%, but the size reduction can depreciate the performance of filter characteristic, especially the third harmonic suppression which showed only a -7dB suppression such a detrimental effect can be alleviated by utilize a spiral defect ground structure(DGS) which devastate a third harmonic suppression of -17 dB. Our propose loop resonator structure induce an improper EM interference at high frequencies. The obvious loss observed in the original structure at the high frequencies can introduce the improper Nevertheless, by using EMI routing technique we can effectively suppress the unwanted loss mechanism and make the circuit more stable in electromagnetic environment. The results of the measurement and simulation are in good agreement within experimental errors and provide a sound experimental verification of our suitable EMI design technique for miniaturization of loop filter. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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