This Thesis is a proposal for a variable bandwidth filter banks using analysis and synthesis filters that is based on polyphase channelizer architecture. Details regarding polyphase configuration and architecture of the up and down converter channelizer will be presented. First, a polyphase channelizer was used to design a variable bandwidth filter banks. Such approach is required for designing a Software Defined Radio receiver and transmitter. Second, the structure of the variable bandwidth was modified to enhance the resolution. The finer resolution will help to improve the quality of extracting the channel of interest from a mixture of different channels. Details regarding our proposed cascaded M-path channelizer filter will be presented. The first stage of the filter will recover the coarse channel while the second stage will focus on the recovery of finer bandwidth. Analysis results of a successful recovery for different signals with different bandwidths will be demonstrated. Multiple configurations of the proposed filter will be studied and simulation results will be presented.