A Low-Voltage Tunable Channel Selection Filter for WiMAX Applications

Authors: Kayvan Ahmadi, Hossein Shamsi

Abstract:

This paper proposes a low-voltage and low-power fully integrated digitally tuned continuous-time channel selection filter for WiMAX applications. A 5th-order elliptic low-pass filter is realized in a Gm-C topology. The bandwidth of the fully differential filter is reconfigurable from 2.5MHz to 20MHz (8x) for different requirements in WiMAX applications. The filter is simulated in a standard 90nm CMOS process. Simulation results show the THD (@Vout =100mVpp) is less than -66dB. The in-band ripple of the filter is about 0.15dB. The filter consumes 1.5mW from a supply voltage of 0.9V.

Keywords: Common-mode feedback, continuous-time, fully differential transconductor, Gm-C topology, low-voltage

Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1335090

References:

[1] D.-R. Huang, S.-W. Kao, and Y.-H. Pang, "A WiMAX Receiver with Variable Bandwidth of 2.5 - 20 MHz and 93 dB Dynamic Gain Range in 0.13-╬╝m CMOS Process", IEEE Radio Frequency Integrated Circuits Symposium, June 2007, pp. 369-372.
[2] S. Hori, T. Maeda, H. Yano, N. Matsuno, K. Numata, N. Yoshida, Y. Takahashi, T. Yamase, R. Walkington, and H. Hida, "A Widely Tunable CMOS Filter With Neg- ative Source Degeneration Resistor Transconductor", IEEE Solid-State Circuits Conference, Sept. 2003, pp. 449- 452.
[3] J. Jiang; Y. Wang, "Design of A Tunable Frequency CMOS Fully Differential Fourth-order Chebyshev Filter", Elsevier, Microelectronics Journal, vol. 37, June 2006, pp. 84-90.
[4] D.A. Johns and K.W. Martin, Analog Integrated Circuit Design, Wiley, New York, 1997.
[5] T. sanchez-Rodriguez, C.I. Lujan-Martinez, R.G. Carvajal, J. Ramirez- Angulo and A. Lopez-Martin, "CMOS Linear Programmable Transconductor Suitable For Adjustable Gm-C Filters", Electronics Letters, vol. 44, no. 8, April 2008, pp. 505-506.
[6] E. Sanchez-Sinencio, "Common-mode Feedback Techniques: A Tutorial", Texas A&M University, Feb. 2005.
[7] U. Stehr, F. Henkel, L. Dalluge, P. Waldow, "A Fully Differential CMOS Integrated 4th Order Reconfigurable Gm-C Lowpass Filter for Mobile Applications", IEEE International Conference on Electronics, Circuits and Systems (ICECS), vol. 1, Dec. 2003, pp. 144-147.