A High Q Gm-C Filter for Multi-band Wireless Applications

In this paper, a full CMOS six-order Gm-C Chebyshev filter based on passive LC-ladder synthesis is designed in TSMC standard 0.25mum CMOS process, which uses a highly linear operational transconductance amplifier (OTA) based on cross-coupled differential pairs, which exhibits a wide product of gain and bandwidth. A common-mode feedback (CMFB) with improved stability is introduced. The simulated results show the center frequency tuning range of the filter is from about 1.5MHz to 11 MHz and the maximum quality factor of 150 at the center frequency 6MHz. The filter is suitable for multi-band wireless applications