
Most Recent Posts
 Using Companion Models for TimeDomain Simulation of ODE’s
 CNC Router & Interview Questions
 Book chapter added on Direct Digital Synthesis
 Updated Filter Design Documentation
 New Programming Projects 26Dec2012
 New Book Chapter
 New Article in Microwaves and RF Out
 New Article in May Microwaves & RF
 Approximation for RMS
 Computing Data Windows Recursively
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Archive for the Category: Mathematics
Using Companion Models for TimeDomain Simulation of ODE’s
Companion models can be used to quickly formulate the solution of simultaneous ordinary differential equations like those associated with analog circuitry. This approach is particularly helpful when this capability must be embedded in tools like MATLAB / SIMULINK / C++. The PDF file is located by following this link.
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Updated Filter Design Documentation
Major revision to my filter design documentation 5.74 MB
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Approximation for RMS
Approximation for SQRT( I2 + Q2 ) with Gaussian Noise Present When a complex signal is represented in terms of inphase (I) and quadraturephase (Q) components, a commonly used approximation for the signal rootmeansquare (RMS) value is Assuming a large number of OFDM subcarriers in the intended application, I and Q appear to both be […]
Also posted in Digital Signal Processing Leave a comment
Computing Data Windows Recursively
Data windows are indispensable for computing the spectral characteristics of signal waveforms that are not periodic in time. In the context of hardwarebased digital signal processing, most if not all data windows are expressed in terms of fairly complex function that are not convenient for embedding in a FPGA or custom ASIC. This memo presents […]
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Dreaded Interview Questions Just for Fun Part I
James A Crawford Having reached a sufficient station in life that I have either heard most of the typical interview questions that might come my own direction, or have the wit and nonsense to navigate my way through something that I don’t know and talk about the weather or something completely unrelated, this ongoing collection […]
Digital ReDesign of Analog PhaseLocked Loops
Abstract The need frequently arises to design a discretetime digital signal processing (DSP) algorithm that closely mimics a conventional continuoustime phaselocked loop (CTPLL). Similarly, it is often desirable to talk about the DSP implementation in terms of traditional quantities like damping factor and equivalent noise bandwidth. This memorandum examines this interplay between discrete and continuous […]
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Pendulum & Elliptic Integrals
Many years ago before the advent of the “PC on every desktop” age, I became fascinated with the design of LC elliptic filters. As part of that endeavor, I also became intimately acquainted with elliptic integrals. Having an equal intrigue for numerical precision, I found that computing the elliptic integrals with high accuracy was very […]
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