English

About the Phasor Pathways in Analogical Amplitude Modulation

Popular Physics 2015-02-11 v1

Abstract

The Phasor diagrams have long been used in Physics and Engineering. In telecommunications, this is particularly useful to clarify how the modulations work. This paper addresses rotating phasor pathways derived from different standard Amplitude Modulation Systems (e.g. A3E, H3E, J3E, C3F). A cornucopia of algebraic curves is then derived assuming a single tone or a double tone modulation signal. The ratio of the frequency of the tone modulator (fm) and carrier frequency (fc) is considered in two distinct cases, namely: fm/fc<1 and fm/fc>=1. The geometric figures are some sort of Lissajours figures. Different shapes appear looking like epicycloids (including cardioids), rhodonea curves, Lemniscates, folium of Descartes or Lam\'e curves. The role played by the modulation index is elucidated in each case.

Cite

@article{arxiv.1502.02947,
  title  = {About the Phasor Pathways in Analogical Amplitude Modulation},
  author = {H. M. de Oliveira and F. D. Nunes},
  journal= {arXiv preprint arXiv:1502.02947},
  year   = {2015}
}

Comments

10 pages, 15 figures. ISSN 2320-9364

R2 v1 2026-06-22T08:26:40.908Z