Abstract: This paper presents a 5th-order Chebyshev-I active RC complex filter for multi-mode multi-band global navigation satellite systems (GNSS) RF receivers. An improved passive compensation technique is used to cancel the excess phase lag of the integrators, thus ensuring the in-band flatness of the frequency response over various ambient conditions. The filter has a programmable gain from 0 to 42 dB with a 6 dB step, a tunable center frequency at either 6.4 MHz or 16 MHz, and a bandwidth from 2 to 20 MHz with less than 3% frequency uncertainty. Implemented in a 0.18 μm CMOS process, the whole filter consumes 7.8 mA from a 1.8 V supply voltage and occupies a die area of 0.4 mm².

Key words: complex filter