The complex envelope is a baseband analytic signal. It is obtained by suppressing the negative (or positive) frequencies of a real bandpass signal, and transferring the remaining spectral content to baseband. Due to the complex notation and the spectral efficiency of the resulting signal, the complex envelope is very useful in both linear system simulation […]
The analytic signal is a complex representation of a real signal, obtained by suppressing the negative frequency components of the original signal. From the analytic signal is derived the equivalent baseband signal, also an analytic representation known as complex envelope. Both representations are used in signal processing techniques due to their main advantages: spectral efficiency […]
The mathematics of linear distortion only applies to linear and time invariant systems [1] [2]. Therefore, these systems and their translation to the frequency domain, where the mathematical analysis is simplified, are briefly summarized. Then it is discussed how the presented theory can be applied to real transmission media and/or electronic components. Finally, the mathematics […]
Nowadays, in any technical work of a certain level, it is common to program and simulate codes in mathematical simulators such as Matlab, or its free “equivalent” Octave. Typically the results of these simulations can be part of documents, presentations and meetings. On many occasions we could benefit from motion graphics to better visualize, explain […]
(Originally published as The Magicians) Breakthrough by Marcus Chown is a popular science book that is sure to please technical profiles, engineers and technology lovers. Through a solid narrative of several amazing discoveries in the world of physics, the author raises and discusses a question that intrigues scientists: Why is mathematics able to describe the […]
The prefix Qucs (Quite Universal Circuit Simulator) refers to a family of electronic circuit simulators that can be used for free: Qucs Original, Qucs-S and QucsStudio. All variants have a very powerful and effective graphical interface, which is even better designed than that of other paid tools. This makes this simulator very attractive for all […]
The Hilbert transform is a linear operation applied to real signals. In practical terms, the Hilbert transform translates into a phase shift of -90º at the positive frequencies (and +90º at the negative frequencies) that make up the signal. The relevance of the Hilbert transform in telecommunication engineering is due to its contribution in obtaining […]
The Fourier transform makes it possible to obtain the components that make up a signal in the transformed domain. In the most common case, the Fourier transform of temporal signals provides the frequencies (ω) that make up the signal. Equivalently, the spatial Fourier transform, applied on a signal defined in space, provides its components typically […]
DIY Project: Redesigning and Building the Electronic Board of a Remote Control Car. Developed and written by Niva_v_Kopirce. Christmas came and I was getting ready to give my nephew a cheap Chinese car. I always like to check beforehand if any gift containing electronic components works. It worked fine, however, I instantly noticed a few […]
In communications, signal propagation theory studies the movement of signals from the transmitter to the receiver through a transmission medium. Depending on the characteristics of the signal and the medium, different situations may arise. In general, the cases are classified according to the type of distortion they produce in the transmitted signal. This text is […]