An Equalized Ultra-Wideband Channel-Select Filter with a Discrete-Time Charge-Domain Band-Pass IIR Filter

An ultra-wideband channel-select filter with equalized pass-band characteristics has been implemented with a 0.13 mum CMOS technology. A discrete-time charge-domain IIR band-pass filter is used to compensate degradation of the 3rd-order continuous-time LC-LPF and the sine response of the 1st-order charge-domain LPF, thus significantly equalizing the total filter response through clock signals. Measurements show that the IIR BPF reshapes the pass-band, allowing a 3-dB bandwidth of 500 MHz with a notch at 1 GHz. The total filter, including 3rd-order LC-LPF, 1st-order sine LPF, 1st-order IIR BPF, and clock generator, dissipates 18.8 mW from a 1.2-V supply voltage.