Help me on 1/f noise calculation!

Below are the equation for MOSFET of 1/f

Vn(1/f noise) = rt[(Kf*gm*gm)*r0*r0/(f*Cox*W*L)]

where Kf = Flicker noise coefficient
f = frequency
r0 = output resistance of the circuit

Problem

1. What is the value of the ferquency? f3db@GBW@frequency that we pick?

Example

kf = 2f
gm = 2.83m
Cox = 1.132m
(W/L) = 102u/1.2u
r0 = 1955
f = 2.66 GHz (Pick any values,example 2.66GHz)

Vn(1/f noise) = rt[(2f*2.83m*2.83m)*1955*1955/(2.66G*1.132m*102u*1.2u)]

= 14.52 uV/rt(Hz)

But...in simulation, it gives 9.8 uV/rt(Hz)!

Is my calculation is true?
Hope someone could help!

One clue is that the two answers are related by the factor square root of 2. This points to peak vs. RMS or other such things.

Did you mean Calculation = Simulation*rt[2] ?

I've tried to calculate them but still don't get the exatc value!

Simulation = 9.8 uV/rt[Hz]
Calculation = 14.52 uV/rt[Hz]

New Equation = 9.8u*rt[2]
= 13.85 uV/rt[Hz]
* Differ about 0.67u, is this value is acceptable?

Sorry to ask a silly question...
I'm 'blur' on noise analysis... 8O

Below are my netlist file and the waveform!

* Main circuit: simple amp-resistor
M1 out in Gnd Gnd NMOS L=1.2u W=102u AD=66p PD=24u AS=66p PS=24u
R2 Vdd out 2k TC=0.0, 0.0
v3 N2 Gnd 0.0 AC 1.0 0.0
v4 in N2 1
* End of main circuit: simple amp-resistor

vvdd Vdd 0 3

*N97N SPICE LEVEL1 PARAMETERS* TECHNOLOGY: SCN12 FEATURE SIZE: 1.2 microns
*COMMENTS: American Microsystems, Inc. 1.2 micron ABN.
* DATE: Sep 13/99
* LOT: n97n WAF: 04
.MODEL NMOS NMOS LEVEL=3 PHI=0.700000 TOX=3.0500E-08 XJ=0.200000U TPG=1
+ VTO=0.6063 DELTA=4.7620E-01 LD=1.2100E-07 KP=7.6456E-05
+ UO=675.3 RSH=6.8720E+01 GAMMA=0.6693
+ NSUB=1.7300E+16 NFS=5.9080E+11 VMAX=2.0890E+05
+ KAPPA=3.8640E-01 CGDO=2.0549E-10 CGSO=2.0549E-10
+ CGBO=4.4943E-10 CJ=2.8197E-04 MJ=5.3962E-01 CJSW=1.3603E-10
+ MJSW=1.0000E-01 PB=9.9000E-01 KF=2.0E-15
* Weff = Wdrawn - Delta_W
* The suggested Delta_W is 1.4000E-06

.ac DEC 5 1k 1000G
.noise v(out,in) v3
.temp 17
.print noise dn(M1,FN) *print 1/f noise for M1*

I've tried to use the factor of rt[2] but it can't be used for lower freq!

Example

Simulation = 74 uV/rt[Hz]
Calculation = 74.9 uV/rt[Hz]

New Equation = Simulation*rt[2]
= 74u*rt[2]
= 105.9 uV/rt[Hz] - differ with previous calculation=74.9 uV/rt[Hz]

Help me....