Theoretical Analysis of Low Phase Noise Design of CMOS VCO

Yao-Huang Kao; Meng-Ting Hsu; Microwave and Wireless Components Letters, IEEE [see also IEEE Microwave and Guided Wave Letters] Volume 15, Issue 1, Jan. 2005 Page(s):33 – 35 Digital Object Identifier 10.1109/LMWC.

2004.840974(410) 15

級 別 : 碩 一學 生 : 許 晉 榕

Outline

Introduction PHASE NOISE IN CROSS-COUPLED LC

VCO MEASUREMENT AND DISCUSSION CONCLUSION

Introduction

phase noise for integrated complementary metal oxide semiconductor (CMOS) voltage

controlled oscillators (VCO) is an essential topic of research. The feasible design procedure and structur

e to obtain the low phase noise is still in progress .

PHASE NOISE IN CROSS-COUPLED LC VCO

Varactor the PMOS is used because of the wide tuning capability and low phase noise.

But the quality factor of the tank is still limited mainly by the performance of the inductor

Measured VCO transfer function

A symmetric waveform is helpful to get the lower 1/f 3 corner in phase noise.

MEASUREMENT AND DISCUSSION

phase noise is demonstrated with 116 dBc/Hz at 600 kHz offset

(1)

=(-116)+10log[(600 X 106 /

2]2 X22.626 =-172.91(dBc)

　　　

　　　

COMPARISON WITH SOME REPORTED PAPERS BASING ON THE SAME STRUCTURE AND RELATED TECHNOLOGY

CONCLUSION

From the procedure of optimization steps, the excess noise factor of the amplifier coming from the active device has been determined. The oscillator is implemented by the standard 0.35- m CMOS technology with phase noise 116 dBc/Hz at 600 kHz offset.