CMOS RFICNoise Canceling Method

2009314086 An Yong-jun

Contents

Noise Cancelling in Wideband CMOS LNAsF. Bruccoleri, E.A.M. Klumperink, B. Nauta. In 2002, ISSCC

Paper Study Flow

Noise Cancelling in Wideband CMOS LNAs

F. Bruccoleri, E.A.M. Klumperink, B. Nauta. In 2002, ISSCC

Today

SameCircuit

Noise Cancelling in Wideband CMOS LNAs

Shunt FeedbackFor input matchingZin = Rs NF>3dBNF always lager than 3dB

Input noise current(ACL-1)times smaller than the others

Noise Cancelling in Wideband CMOS LNAs

Noise Canceling from MOSFET(Not source)

Determine ‘A’

Wide-Band CMOS Low-Noise Amplifier Exploiting Thermal Noise Canceling

Same Opposite

Wide-Band CMOS Low-Noise Amplifier Exploiting Thermal Noise Canceling

Overall Gain :

Wide-Band CMOS Low-Noise Amplifier Exploiting Thermal Noise Canceling

Source FollowerVout = VYout+VXout

VYout = VY

VXout = VX * gm2/gm3

Noise cancelled which is gen-erated by this FET

Wide-Band CMOS Low-Noise Amplifier Exploiting Thermal Noise Canceling

EF : (noise)Excess Factor

Higher gm2Rs Lower F

Less than 1

Wide-Band CMOS Low-Noise Amplifier Exploiting Thermal Noise Canceling

Noise cancelled point!

Wide-Band CMOS Low-Noise Amplifier Exploiting Thermal Noise Canceling

Wide-Band CMOS Low-Noise Amplifier Exploiting Thermal Noise Canceling

►Robustness

Wide-Band CMOS Low-Noise Amplifier Exploiting Thermal Noise Canceling

►Distortion canceling

Distortion comes from this FET

Distortion canceled like Thermal noise

Wide-Band CMOS Low-Noise Amplifier Exploiting Thermal Noise Canceling

►High Freq. Limit.

Approximately CY=CL=0 1) CY and the load CL don’t affect the can-cellation

2) CL doesn’t affect the F of the LNA standalone

Source Impedance looks like

Wide-Band CMOS Low-Noise Amplifier Exploiting Thermal Noise Canceling

@ High Freq, Noise cancelling is degraded

Wide-Band CMOS Low-Noise Amplifier Exploiting Thermal Noise Canceling

But f0 is higher, - high fT

- Minimizing CIN

- reduce Miller effect

degrades frequency factor

Wide-Band CMOS Low-Noise Amplifier Exploiting Thermal Noise Canceling

Wide-Band CMOS Low-Noise Amplifier Exploiting Thermal Noise Canceling

►Conclusion• simultaneous cancellation of noise and distortion terms

due to the matching device;

• simultaneous noise and power matching for frequencies

where the effect of parasitic capacitors can be neglected;

• orthogonality of design parameters for input impedance

and gain, allowing for an easier implementation of variable

gain while maintaining input impedance matching;

• robustness to variations in device parameters and the external

source resistance ;

• applicability in other IC technologies and amplifier

topologies.