SPURLINE RESONATORS DESIGN AND ITS IMPLEMENTATION TO MICROWAVE OSCILLATORS

In this article, two compact L-type spurline and symmetric meander spurline resonators were designed and implemented into low phase-noise microwave oscillators for X-band application. These resonators have a bandstop characteristic that can be used in the series feedback oscillator topology. Both of these miniaturized resonators are designed with different spurline structures, the first one being an L-type spurline and the other one a meander spurline. Both resonators exhibited inherently inductive characteristics and had a loaded stub with capacitive characteristics. The oscillators using the spurline and the symmetric meander spurline resonators show excellent phase-noise performances of -96.23 dBc/Hz and -104.39 dBc at a 100 kHz offset from the carrier frequency of 9.2 and 9.0 GHz with an output power of 12.47 and 16.42 dBm, respectively. The latter oscillator exhibited better phase-noise characteristics due to the high Q value of the symmetric meander spurline resonator. The figure of merit of the first oscillator achieved - 174, and the latter achieved - 181.36. The size of the oscillator is reduced by constructing a parallel combination of the open stub at the source and the DC voltage supply at the drain (C) 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:171-176, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26461