High-Q, High-Rejection Ratio Complex Second-Order Charge-Sampling Switched gm-C Semi-Passive Band-Pass Filter

Abstract

In this paper, a complex second-order charge-sampling switched [Formula: see text]-[Formula: see text] semi-passive band-pass filter (BPF) is presented which by using the technique of increasing the number of input signal phases without the need to increase the number of clock phases and switches, has been improved out-of-band rejection, near-band rejection and the quality factor of the filter. In addition to the tunable bandwidth and center frequency that can be tuned independently, the proposed filter provides a very high linearity and consumes low power. Designed and simulated in a [Formula: see text]m standard CMOS technology, this filter operating at 1[Formula: see text]GS/s sampling rate has an adjustable center frequency of 11.68–28.5[Formula: see text]MHz and a tunable bandwidth of 1.8–8.74[Formula: see text]MHz. Also, the out-of-band rejection varies from 37[Formula: see text]dB to 39[Formula: see text]dB in an offset frequency of 3 fc. The in-band IIP3, power consumption and input-referred noise are 28[Formula: see text]dBm, 5[Formula: see text]mW and 13.8–18.8[Formula: see text]nv/sqrt (Hz), respectively