Interpolator Design: Get the Stopbands Right

Neil Robertson

In this article, I present a simple approach for designing interpolators that takes the guesswork out of determining the stopbands.

Return of the Delta-Sigma Modulators, Part 1: Modulation

Jason Sachs

About a decade ago, I wrote two articles: Modulation Alternatives for the Software Engineer (November 2011) Isolated Sigma-Delta Modulators, Rah Rah Rah! (April 2013) Each of these are about delta-sigma modulation, but they’re...

Simple Discrete-Time Modeling of Lossy LC Filters

Neil Robertson

There are many software applications that allow modeling LC filters in the frequency domain.  But sometimes it is useful to have a time domain model, such as when you need to analyze a mixed analog and DSP system.  For example, the...

The Discrete Fourier Transform as a Frequency Response

Neil Robertson

The discrete frequency response H(k) of a Finite Impulse Response (FIR) filter is the Discrete Fourier Transform (DFT) of its impulse response h(n) [1].  So, if we can find H(k) by whatever method, it should be identical to the DFT of...

Simple Concepts Explained: Fixed-Point

Leandro Stefanazzi

IntroductionMost signal processing intensive applications on FPGA are still implemented relying on integer or fixed-point arithmetic. It is not easy to find the key ideas on quantization, fixed-point and integer arithmetic. In a series of...

Overview of my Articles

Cedron Dawg

Introduction This article is a summary of all the articles I've written here at DspRelated. The main focus has always been an increased understanding of the Discrete Fourier Transform (DFT). The references are grouped by topic and ordered in...

Add the Hilbert Transformer to Your DSP Toolkit, Part 2

Neil Robertson

In this part, I’ll show how to design a Hilbert Transformer using the coefficients of a half-band filter as a starting point, which turns out to be remarkably simple.  I’ll also show how a half-band filter can be synthesized using the...

Add the Hilbert Transformer to Your DSP Toolkit, Part 1

Neil Robertson

In some previous articles, I made use of the Hilbert transformer, but did not explain its theory in any detail.  In this article, I’ll dig a little deeper into how the Hilbert Transformer works.  Understanding the Hilbert Transformer...

Candan's Tweaks of Jacobsen's Frequency Approximation

Cedron Dawg

Introduction This is an article to hopefully give a better understanding of the Discrete Fourier Transform (DFT) by explaining how a tweak to a well known frequency approximation formula makes it better, and another tweak makes it exact. The...