Post on 28-Mar-2015
Ischia, 21-23 giugno 2006Riunione Annuale GE 2006
Università di CataniaFacoltà di IngegneriaDIEESCatania - ITALY
STMicroelectronicsCatania site
Lumped Modeling of Lumped Modeling of Differentially Driven Differentially Driven
Symmetric Inductors for RF Symmetric Inductors for RF IC DesignIC Design
Egidio Ragonese, Angelo Scuderi, Tonio Biondi, Alessandro Italia, and Giuseppe Palmisano
Radio Frequency Advanced Design Center (RF-ADC)
Sistemi Elettronici Integrati – B25
Ischia, 21-23 giugno 2006Riunione Annuale GE 2006
IntroductionIntroduction In RF ICs symmetrical inductors are profitable
exploited instead of two separate spirals lower area full electrical symmetry higher Q-factor and fSR
A profitable exploitation of integrated inductors requires simple, accurate and geometrically scalable models
Most inductor models are developed only for single-ended spirals, while the few models for symmetric inductors are not validated for single-ended structures
Ischia, 21-23 giugno 2006Riunione Annuale GE 2006
Modeling of integrated inductors Modeling of integrated inductors on Sion Si
Both single-ended and differential inductors were fabricated using a bipolar process supplied by ST-Microelectronics
Turn number from 1 to 5.5, inner diameter from 50 to 150 µm and metal width from 6 to 20 mm
Ischia, 21-23 giugno 2006Riunione Annuale GE 2006
Modeling of integrated inductors Modeling of integrated inductors on Sion Si
A scalable model for both single-ended and differential inductors
Modified -like topology (only one fitting parameter)
Physics-based equations based on process/layout parameters
Improved current sheet expression of LS (for sub-nH inductors)
Novel equation for series resistance (current crowding)
K·LS K·RS (1-2K)·LS (1-2K)·RS
CS Z1
K=0.16
RG CG
COX
K·LS K·RS
Z2
CG
COX
RG
Ischia, 21-23 giugno 2006Riunione Annuale GE 2006
Model validationModel validation Model validation up to 20 GHz by comparison with on-
wafer measurements of more than 100 spirals (covering 0.2 to 8.3 nH inductance values)
Accuracy, geometrical scalability and compactness promote the model as a reliable time-saving design tool
Average errors on inductance, fSR and Q
are 2%, 5%, and 7%
Ischia, 21-23 giugno 2006Riunione Annuale GE 2006
Model exploitationModel exploitation:: A 5-GHz image-reject down-A 5-GHz image-reject down-
converterconverter Extensively exploitation of integrated inductors (designed
with the proposed model)
Differential inductors are used in image-rejection filters
Ischia, 21-23 giugno 2006Riunione Annuale GE 2006
Model exploitation Model exploitation A 5-GHz image-reject down-A 5-GHz image-reject down-
converterconverter
Ischia, 21-23 giugno 2006Riunione Annuale GE 2006
See you later….See you later….
Poster B25Poster B25