Spectral Analysis – a Fourier transform tutorial – part #5

04/08/2011

This part of the tutorial demonstrates the Fourier transform operation in a few cases of periodic and aperiodic signals, such as an AM signal, an FM signal, a rectangular nonrepetitive signal and a cardinal sinus signal. The last slide contains an application to the scaling property of the Fourier transform on a nonrepetitive time signal. It actually shows that spreading a signal in the time domain shrinks its spectrum and…

Spectral Analysis – a Fourier transform tutorial – part #4

04/07/2011

The previous sections explaind the creation of a discrete Fourier transform model in Excel. This section and the following one will use the model to calculate and chart the Fourier transform in several cases of periodic and aperiodic signals. [sociallocker][/sociallocker]

Spectral Analysis – a Fourier transform tutorial – part #3

03/30/2011

While the previous sections of the tutorial handled the basic formulas behind building a Fourier model and creating a set of input functions, this section deals with formula implementation on the spreadsheet, the brief VBA code and the charting of the Fourier transform components. [sociallocker][/sociallocker]

Spectral Analysis – a Fourier transform tutorial – part #2

03/29/2011

In this tutorial the Excel implementation of a Fourier transform is discussed. Seven input signals are created among which sinusoidal, rectangular and combinations of them. A Dirac impulse, an amplitude modulated (AM) signal and a frequency modulated (FM) signal are also added among the input signal options. [sociallocker][/sociallocker]

Spectral Analysis – a Fourier transform tutorial – part #1

03/28/2011

This is a basic tutorial about implementation of a standard Fourier transform model in Excel. It is not an introduction to Fourier analyis. You could choose to familiarize yourself with the subject before proceeding with this tutorial. Solving a few Fourier transform excersises would be of help too. Essentially, this part shows you how to adapt the general Fourier formula for a continuous real signal to a sampled signal having a limited number of samples.

How to Model a Phase-Locked Loop (PLL) in Excel – part#4

03/14/2011

This last section of introductory PLL modeling shows how to upgrade the model with  adjustable scale charts for three voltage signals within the loop. The model also shows how to create a Lissajous based phase display. [sociallocker][/sociallocker]

How to Model a Phase-Locked Loop (PLL) in Excel – part#3

03/13/2011

This is a continuation of the PLL series of tutorials and it takes the recursive numerical formulas derived in the previous section, implementing a dynamic spreadsheet  model with help from a copy-paste loop type of macro. This macro emulates the behavior of the phase locked loop model in time. At this point, the model is functional. Charting options for the waveforms will be discussed in the following section. [sociallocker][/sociallocker]

How to Model a Frequency Modulated (FM) Signal – an insight

03/12/2011

Both frequency and phase modulation are important not only in electronics but also in science and physics in general. It seems like a trivial chore but when I first tried to model such a signal some time back I hit a hard wall. Our minds easily understand kinematics concepts such as coordinate, speed, acceleration and the relations between them in real life situations, but phase, frequency and angular acceleration are…

How to Model a Phase-Locked Loop (PLL) in Excel – part#2

03/11/2011

This is a continuation of the PLL series of tutorials and it starts by implementing and testing the low pass filter created in the previous section. After that, the block diagram is updated and the presentation begins to show how to build the PLL model in a worksheet using the existing LPF formulas. [sociallocker][/sociallocker]

How to Model a Phase-Locked Loop (PLL) in Excel – part#1

03/09/2011

A Phase-Locked Loop is a type of electronic circuit. It generates an oscillation with the same frequency as a reference oscillation and a relatively constant phase difference  with respect to the same reference. The applications spectrum of such a circuit are extremely wide. Signal modulation, demodulation, detection and filtering, frequency conversion and synthesis are just a fraction of what this circuit can do. Though very simple, it is often not enough understood in industry by…