Simple circuit model of small loop antenna including observable environmental effects [comment]

For original paper see M.J. Underhill and M. Harper, ibid., vol.38, pp.1006-7 (2002). The approach adopted in the above paper appears to be entirely empirical and is not helped by unfortunate typographical errors. As a result, the conclusions reached regarding the characteristics of electrically small loop antennas appear to be flawed. The subject has been examined over many years but no reference is made to the extensive literature, of which just some is listed in this comment. This previous work is of particular importance since these antennas are constrained in their performance by fundamental limitations and thus they constitute a special class of radiating structure characterised, generally, by low radiation efficiency and narrow bandwidth.