The most computationally demanding block in the digital front end (DFE) of a software defined radio (SDR) is the channelizer which operates at the highest sampling rate. Channelizers are employed in the SDR receivers for extracting individual channels from the digitized wideband input signal. Reconfigurability and low complexity are the two key requirements of channelizers in SDRs. A new reconfigurable filter bank (FB) architecture based on an interpolation and masking technique for SDR channelizers is proposed in this paper. The proposed FB offers reconfigurability at the architectural level and at the channel filter level, and is capable of extracting channels of different bandwidths corresponding to multiple wireless communication standards from the digitized wideband input signal. Design example shows that the proposed FB offers complexity reduction of 89.9% over the conventional per-channel (PC) approach, 79.8% over DFT filter banks (DFTFBs) ©2007 IEEE.