A method to lower VCO phase noise by using HBT darlington pair
Paper in proceeding, 2012
The paper presents a novel method to enhance tank voltage swing in LC VCOs design using bipolar transistor. The method is successfully demonstrated in an InGaP/GaAs HBT MMIC process. A gm-boosted VCO and a modified version, using Darlington-pair transistors, are compared. The latter exhibits lower phase noise, increased tuning range, and less variation in output power. The gm-boosted VCO has tuning range of 22.8% centered at 5.7GHz and phase noise ranging from 103 to 95 dBc/Hz at offset frequency of 100kHz. The modified version using Darlington pair has tuning range of 26% centered at 5.9 GHz and phase noise ranging from 103.5 to 98.5 dBc/Hz at offset frequency of 100kHz.
HBT
MMIC
Phase-noise
VCO
Darlington pair
Author
Szhau Lai
GigaHertz Centre
Chalmers, Microtechnology and Nanoscience (MC2), Microwave Electronics
M. Bao
Chalmers University of Technology
Dan Kuylenstierna
GigaHertz Centre
Chalmers, Microtechnology and Nanoscience (MC2), Microwave Electronics
Herbert Zirath
GigaHertz Centre
Chalmers, Microtechnology and Nanoscience (MC2), Microwave Electronics
IEEE MTT-S International Microwave Symposium Digest
0149645X (ISSN)
6259421978-146731087-1 (ISBN)
Subject Categories (SSIF 2011)
Electrical Engineering, Electronic Engineering, Information Engineering
DOI
10.1109/MWSYM.2012.6259421
ISBN
978-146731087-1