Design of Low Phase-Noise Oscillators and Wideband VCOs in InGaP HBT Technology
Magazine article, 2012

A method for design of low phase-noise balanced-Colpitts (BC) fixed-frequency oscillators (FFOs) and wideband voltage-controlled oscillators (VCOs) is presented. Analytical expressions describe how to design an oscillator for best phase noise, given a limited Q factor and a certain active device. The theory needs only two free parameters: the impedance (Z(c)) level and tapping ratio (n) of the resonator. It is described how to chose Z(C) and n for low phase noise and large tuning range, respectively. The design method is verified with a low phase-noise FFO and a wideband VCO, both designed in InGaP HBT technology. The BC FFO presents a phase noise of -112 dBc/Hz at 100-kHz offset from a 9.2-GHz carrier. The wideband VCO implemented in the same technology presents a minimum phase noise of -106 dBc/Hz at 100-kHz offset from a 9-GHz carrier. Over the frequency range of 8.4-9.7 GHz, the phase noise is better than -102 dBc/Hz and the output power is 7 +/- 0.5 dBm. The wide tuning range, constant output power, and relatively constant and low phase noise are achieved due to double pairs of tuning varactors, one between emitters and one between collectors. To the authors' best knowledge, this type of double-tuned BC VCO topology has not been previously published.

tuning range

oscillator

Balanced Colpitts (BC)

colpitts vco

double tuned

voltage-controlled oscillator (VCO)

phase noise

model

Author

Dan Kuylenstierna

Chalmers, Microtechnology and Nanoscience (MC2), Microwave Electronics

GigaHertz Centre

Szhau Lai

GigaHertz Centre

Chalmers, Microtechnology and Nanoscience (MC2), Microwave Electronics

M. Q. Bao

Ericsson Microwave Systems AB

Herbert Zirath

GigaHertz Centre

Chalmers, Microtechnology and Nanoscience (MC2), Microwave Electronics

IEEE Transactions on Microwave Theory and Techniques

0018-9480 (ISSN)

Vol. 60 11 3420-3430

Subject Categories

Electrical Engineering, Electronic Engineering, Information Engineering

DOI

10.1109/tmtt.2012.2216893

More information

Created

10/7/2017