A Historical Note on Impedance-Matching Limitations [Antenna Designer's Notebook]

In Chu's classic 1948 paper, he presented results that related the theoretical lower bound on Q to the antenna's size for an electrically small antenna. He also presented results that related the theoretical upper bound on the impedance-matching bandwidth, the tolerable reflection magnitude, and the antenna's size. These latter results, which have not been fully appreciated, are highlighted in this concise article.