Accurate Phase-Noise Prediction for a Balanced Colpitts GaN HEMT MMIC Oscillator

作者：Lai Szhau^*; Kuylenstierna Dan; Horberg Mikael; Rorsman Niklas; Angelov Iltcho; Andersson Kristoffer; Zirath Herbert

来源：IEEE Transactions on Microwave Theory and Techniques, 2013, 61(11): 3916-3926.

DOI：10.1109/TMTT.2013.2282131

• Cyclo-stationary noise
• GaN HEMT
• low-frequency (LF) noise
• monolithic microwave integrated circuit (MMIC)
• oscillator
• phase noise

This paper presents an X-band balanced Colpitts oscillator in GaN HEMT technology and a method to calculate its phase noise accurately. The method employs a low-frequency (LF) noise measurement and the oscillator waveforms from a harmonic-balance simulator. These data are post-calculated by Hajimiri's phase-noise model, in which the LF noise can be activated with a cyclo-stationary effect in the calculation of phase noise. Compared to commercial phase-noise simulation using predefined stationary noise, the calculation gives significantly improved phase-noise prediction in the 30-dB/decade region near carrier. The prediction is within 3-dB accuracy at 10-kHz, 100-kHz, and 1-MHz offset frequencies. In addition to the method used for phase-noise prediction, the potential for wideband tuning of this oscillator topology is analytically investigated. The measured phase noise of the oscillator is -102 dBc/Hz at 100-kHz offset from a 8.6-GHz carrier frequency for drain voltage and current of Vd = 15 V amd Id = 40 mA.

• 出版日期2013-11