Analog Filter Design
Dr. Rolf Schaumann
Professor Schaumann’s research interests are in the areas of filters and analog
integrated circuits. In particular, we are working on the realization of fully
integrated analog filters in CMOS technology for applications at very high
frequencies. The work involves the development of fast, electronically tunable
building blocks (transconductors and integrators). The circuits should be adaptive
and self-tuned against fabrication tolerances, aging, changing operating conditions,
such as temperature. Related issues are the design of high-Q inductors on an IC
chip, and the development of design-automation systems for the automatic
synthesis and layout of filters. Our work has resulted in some 150 publications and
several books and book chapters.
Microphoto of the processed IC (top
left corner if #3).
Layout of the 26.6 um x 30
um filter core.
Student Haiqiao Xiao and professor
Schaumann in the lab
Simulated performance of the
filter.(the input impedance of the
circuit; the transfer function is just a
scaled version of Zin)
Layout of the complete GHzfilter IC.
A section of picture #4. The
central part of this photo
(between the middle two white
bonding pads) contains the GHz
analog filter, i.e., the filter core
(picture #6) between two buffer
amplifiers.
The measured transfer function of a high-Q band-pass filter
realized in 0.18-m standard digital CMOS technology.
Center frequency f0 = 5.42 GHz, quality factor Q = 365.
f0, Q and gain are electronically tunable.
Selected Publications
•
Design of Active Filters, R. Schaumann and M. A. Van Valkenburg, Oxford
University Press, New York, 738 pages, Jan. 2001.
•
S. Koziel, S. Szczepanski and R. Schaumann, “A General Approach to
Continuous-Time Gm-C Filters Based on Matrix Descriptions,” Proc. of the IEEE Int.
Symp. on Circuits and Systems (ISCAS ), May 2002.
•
S. Koziel, S. Szczepanski, and R. Schaumann, “Design of a highly linear
tunable CMOS OTA,” Proc. of the IEEE Int. Symp. on Circuits and Systems (ISCAS),
May 2002.
•
H. Xiao and R. Schaumann, “Very-High-Frequency Lowpass Filter Based on
a CMOS Active Inductor,” Proc. of the IEEE Int. Symp. on Circuits and Systems
(ISCAS), June 2002.
•
H. Xiao and R. Schaumann, “A Low-Voltage Low-Power CMOS 5-GHz
Oscillator Based on Active Inductors,” IEEE International Conference on Electronic
Circuits and Systems (ICECS), Dubrovnic, Sept. 2002.
•
S. Koziel, S. Szczepanski and R. Schaumann, “A General Approach to
Continuous-Time GmC Filters,” International Journal of Circuit Theory and
Applications, Vol. 31, pp. 361-383, July/August 2003.
•
S. Koziel, S. Szczepanski and R. Schaumann, “CMOS Differential
Transconductor with Active Error Feedback,” Proc. IECES-2003, pp. 168-171.
•
S. Koziel, S. Szczepanski and R. Schaumann, “Structure Generation and
Performance Comparison of Elliptic Gm-C Filters,” International Journal of Circuit
Theory and Applications, June 1, 2004.
•
H. Xiao, R. Schaumann, W. R. Daasch, P. K. Wong and B. Pejcinovic, “A
Radio-Frequency CMOS Active Inductor and its Applications in Designing High-Q
Filters,” Proc. of the IEEE Int. Symp. on Circuits and Systems (ISCAS), Vol. 4, pp.
197-200, May 2004.
•
S. Koziel, R. Schaumann, and H. Xiao, “Analysis and Optimization of Noise
in Continuous-Time OTA-C Filters,” IEEE Transactions on Circuits and Systems – I,
Vol. 52, pp. 1086 – 1094, June 2005.
•
S. Koziel and R. Schaumann, “Continuous-Time Active-RC Filter Model for
Computer-Aided Design and Optimization,” IEEE Transactions on Circuits and
Systems – I, Vol. 52, pp. 1292 –1301, July 2005.