An oscillator circuit has been developed at Sandia NationalLaboratories that uses inverted-mesa resonators, in a high-precision VCOapplication, at frequencies historically dominated by SAW designs. Thisdesign incorporates a frequency tripler that provides a 600 MHz outputcapability using a 200 MHz 3rd overtone resonator. Thisdesign has some advantages over equivalent SAW alternatives: lowerpower-consumption, superior aging characteristics, linear frequencypulling and low frequency versus temperature sensitivity. The VCOpresented demonstrates >+/-60 ppm pullability (0 to 7V control),tuning linearity better than +/-5% with phase noise at 1 kHz <-110dBc/Hz. This oscillator-tripler exploits the nonlinear characteristicsof an emitter-coupled-pair differential amplifier to obtain ahigh-performance oscillator design
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