1/f Additive Phase Noise Analysis for One-Port Injection-Locked Oscillators

Abstract

The 1/f additive phase noise of one-port injection-locked oscillators is experimentally characterized and analyzed using a simple analytic model based on the generalized 1/f Kurokawa theory. To experimentally verify the prediction of the simple analytic model proposed, two negative-conductance transmission line pHEMT oscillators operating at 2.4828 GHz and 2.485 GHz were designed and fabricated. A new configuration for integrating an additive phase noise measurement system with a large signal network analyzer (LSNA) is introduced to jointly acquire both the noise and RF waveforms of the one-port injection-locked oscillator. The Kurokawa derivatives needed for the analytic expression were experimentally obtained using the LSNA measurements and optimized to accurately model the corner frequency. A good agreement between the predicted and experimental results was obtained for both the injection-locked and free-running oscillators. In contrast to phase noise measurements of the free-running oscillator, which can only characterize the oscillator-upconverted 1/f3 noise, the additive phase noise characterization of the injection-locked oscillator is shown to provide the means to directly observe and characterize the input-referred intrinsic 1/f noise source of the oscillator negative resistance.