Ischia, giugno 2006Riunione Annuale GE 2006 Università di Catania Facoltà di Ingegneria DIEES Catania - ITALY STMicroelectronics Catania site Lumped Modeling of Differentially Driven Symmetric Inductors for RF IC Design Egidio Ragonese, Angelo Scuderi, Tonio Biondi, Alessandro Italia, and Giuseppe Palmisano Radio Frequency Advanced Design Center (RF-ADC) Sistemi Elettronici Integrati – B25

Ischia, giugno 2006Riunione Annuale GE 2006 Introduction In RF ICs symmetrical inductors are profitable exploited instead of two separate spirals lower area full electrical symmetry higher Q-factor and f SR 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, giugno 2006Riunione Annuale GE 2006 Modeling of integrated inductors on 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, giugno 2006Riunione Annuale GE 2006 Modeling of integrated inductors on 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 L S (for sub-nH inductors) Novel equation for series resistance (current crowding)

Ischia, giugno 2006Riunione Annuale GE 2006 Model 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, f SR and Q are 2%, 5%, and 7%

Ischia, giugno 2006Riunione Annuale GE 2006 Model exploitation: A 5-GHz image-reject down-converter Extensively exploitation of integrated inductors (designed with the proposed model) Differential inductors are used in image-rejection filters

Ischia, giugno 2006Riunione Annuale GE 2006 Model exploitation A 5-GHz image-reject down-converter

Ischia, giugno 2006Riunione Annuale GE 2006 See you later…. Poster B25