IMPLEMENTATION OF HIGH QUALITY-FACTOR ON-CHIP TUNED MICROWAVE RESONATORS AT 7 GHz

We report on the design, analytical modeling, numerical simulation, fabrication, and experimental characterization of chip-scale microwave resonators that exhibit high quality-factors (Q-factors) in the microwave frequency range. We demonstrate high Q-factors by tuning these microwave resonators with the film capacitance of their LC tank circuits rather than the conventional approach of using external capacitors for tuning. Our chip-scale resonator design futher minimizes energy losses and reduces the effect of skin depth leading to high Q-factors even for significantly reduced device areas. Using our new design methodology, we observe that despite the higher resonance frequency and smaller chip size, the Q-factor is improved compared with the previous literature using traditional approaches. For our 540 mu m x 540 mu m resonator chip, we theoretically compute a Q-factor of 52.40 at the calculated resonance frequency of 6.70 GHz and experimentally demonstrate a Q-factor of 47.10 at the measured resonance frequency of 6.97 GHz. We thus achieve optimal design for microwave resonators with the highest Q-factor in the smallest space for operation at 6.97 GHz. (C) 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 497-501, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24103