Definition of electrically small antenna Fields of a short,linear electric-current element 1 E= sine e-jkr 7w6 -1 13 kr3 1 Er=-2c080 e-jkr +) 1 2-j Ze Ea=Z。}+1 kr =Re-iX for TM wave kr + IX ”-ky+ER+forTE wave IRI () We often use koa 1 as the standard for ESA2 0 2 4 3 0 2 2 2 2 2 1 ( ) for TM wave ( ) 1 for TE wave 1 ( ) e e e m m m kr j E kr Z Z R jX H kr k k j E r Z Z R jX H k k r r                  3 | | 1 | | ( ) X R kr  Definition of electrically small antenna We often use as the standard fo 0 1 k a  r ESA Fields of a short, linear electric-current element