標題: FLICKER NOISE IN CMOS LC OSCILLATORS国外硕士论文 [打印本頁] 作者: qitianhua 時間: 2009-10-10 09:11 PM 標題: FLICKER NOISE IN CMOS LC OSCILLATORS国外硕士论文 A Thesis Presented to The Academic Faculty5 ~+ \, r* {# U1 u) [
By Dale Scott Douglas In Partial Fulfillment Of the Requirements for the Degree 3 s' h' f4 r. e7 E. a1 W# }Master of Science in Electrical and Computer Engineering3 B/ E) e1 H! D9 t% F0 z
Georgia Institute of Technology ' m; P5 ]& N. J/ `5 A5 }1 ADecember, 2008 ! q/ b) n* v) ^ h& t9 j5 w7 V: P, |* y8 R. t( k9 ^
* Z0 e& _* }$ V+ ?* \7 @' x. BSUMMARY! Z4 ]) m' k. o% r+ t+ l
Sources of flicker noise generation in the cross-coupled negative resistance oscillator 4 W6 c% I# |0 i(NMOS, PMOS, and CMOS) are explored. Also, prior and current work in the area of % z+ D0 i1 {/ s' V5 @* n7 S( g9 Q( X# Y# @phase noise modeling is reviewed, including the work of Leeson, Hajimiri, Hegazi, and / W) r7 j! b V( yothers, seeking the mechanisms by which flicker noise is upconverted. ; C( [% Y: z& S0 Z& r3 E: Q0 |A Figure of Merit (FOM) methodology suitable to the 1/f3 phase noise region is also6 C+ W+ a- s7 y9 f8 |( Z
developed, which allows a new quantity, FOM1, to be defined. FOM1 is proportional to Q5 k# M/ R+ N/ sflicker noise upconverted, thus allowing the effectiveness of flicker noise upconversion: m3 t& _5 T6 }4 b" [' y
suppression techniques to be evaluated, despite possibly changing bias points or tank Q, 5 K7 z0 D( k$ j0 E6 ywhich would change phase noise and FOM in the 1/f2 region.! D, e7 l6 K0 U
The work of Hajimiri is extended with a simple ΛDC estimator for the special case of `; b/ z: C3 I& y# cLC CMOS oscillators. A method of adaptive control of an oscillator core is presented, as / i3 O$ {: G' u2 C! k+ f* iwell, comprised of a CMOS oscillator with a digitally adjustable N and P width, and a# h) ?/ V" m7 A8 z) Q* E% `
circuit (which is essentially a tracking ADC) which repeatedly adjusts the relative N to P2 v: m: d" S- ^. I( s
width dependent on the ΛDC estimate to maintain the condition of minimum flicker noise 2 l8 K% r# E4 w( {. V) wupconversion. A fixed calibration constant is sufficient to allow convergence to within 8 o' U' s1 [5 R! B; w0.7dB of optimal FOM1 for all cases of N width, for a varactorless oscillator test cell.+ V4 @; b. k- C' E
Finally, a circuit is proposed which would allow the flicker noise reduction technique , ^: S( Z; r6 | ~8 G7 A! a1 Jof cycling to accumulation to be applied to continuous time oscillators, but is not e+ @! B) |1 e* O2 Jrigorously vetted.