Electrically short

An electrically short antenna is an antenna of length 2h, such that $2 \pi h\over\lambda$ $\scriptstyle\ll 1$ .^[1] An electrically short transmission line is a transmission line in which all of its effects will complete within one cycle of an impressed alternating current.

References

^ Kraus, John D. (1950). Antennas. McGraw-Hill. Chapter 3, The antenna as an aperture, pp 49.