Abstract
In this thesis, a low-power-consumption multi-bandwidth filter is proposed. There are two operational transconductance amplifiers(OTA) to be designed. One is multi-input and the other is multi-output. By using both OTAs, a six-bandwidth fourth-order Gm-C filter is realized. The six bandwidths are 0.875 MHz, 1.75 MHz, 2.75 MHz, 3.5 MHz, 5 MHz, 10 MHz. Moreover, the bandwidth of the Gm-C filter can be tuned by the transconductance of the OTA. An on-chip automatic frequency tuning system is also designed to compensate. To verify this design, a test chip is fabricated with TSMC 0.18 μm CMOS process and the power supply is 1.8 V. According to the simulation results, total harmonic distortion (THD) is small than 1% when input signal is 1Vppd; IIP3 are more than 5 dBV; P1dB are more than -3 dBV; total capacitors are smaller then 15pF; current consumption is small than 15mA; and bandwidth tuning error is small than 5%.