Advanced filter banks and time interleaving for analog and digital conversion

This paper presents a comparison of Advanced Filter Banks (AFB) and Time-Interleaving for high-speed, high-resolution conversion between analog and digital signals using a parallel array of converters. The AFB is an unconventional class of filter bank that employs both analog and digital signal processing. The AFB improves the speed and resolution of the conversion compared to the standard Time-Interleaved array conversion technique. Gain and phase mismatch errors are analyzed for both the AFB and Time-Interleaving architectures. The filters in the AFB isolate the converters in the array from each other and attenuate the effects of mismatches. In four-channel example systems analyzed in this paper, gain and phase errors are attenuated by 21 dB more in the AFB (with 30 dB stopband attenuation) than in the Time- Interleaved system. The AFB is capable of analog-to-digital conversion with 14-bit resolution and 400 MHz sample rate.