An Improved Recursive and Non-recursive Comb filter for DSP applications

TL;DR

This paper introduces an improved design for recursive and non-recursive comb filters that enhances speed and reduces power consumption in DSP applications, especially at high decimation ratios and filter orders.

Contribution

It presents a novel analysis and design methodology for low power, high-speed comb filters, with implementation strategies using Matlab and Verilog HDL.

Findings

Non-recursive comb filter speeds up circuit operation.

Non-recursive filter reduces power consumption.

Modified Carry Look-ahead Adder improves summation efficiency.

Abstract

The recursive and non-recursive comb filters are commonly used as decimators for the sigma-delta modulators. This paper presents the analysis and design of low power and high-speed comb filters. The comparison is made between the recursive and the non-recursive comb filters with the focus on high speed and saving power consumption. Design procedures and examples are given by using Matlab and Verilog HDL for both recursive and non-recursive comb filter with emphasis on frequency response, transfer function and register width. The implementation results show that non-recursive comb filter has the capability of speeding up the circuit and reducing power compared to recursive one when the decimation ratio and filter order are high. Using Modified Carry Look-ahead Adder for summation and also apply pipelined filter structure makes it more compatible with DSP application.