Analog Filter Design Dr Rolf Schaumann Professor Schaumanns

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 f 0 = 5. 42 GHz, quality factor Q = 365. f 0, 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 Gm. C 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.