The Receiving Antenna in a Plane-Polarized Field of Arbitrary Orientation

The analysis previously made for a center-loaded linear receiving antenna of finite cross section oriented in the plane of a plane-polarized electric field is extended to include arbitrary orientation with respect to a linearly or elliptically polarized field. A general formula for the complex open-circuit voltage at the load terminals is given and this is expressed in terms of a complex effective length. The relation between the magnitude of this effective length and the field characteristic of the same antenna when driven is pointed out. By means of the reciprocal theorem the complex effective length is shown to yield a general expression for the radiation field of a center-driven antenna of nonvanishing radius. This is correlated with the corresponding expression previously obtained using an approximate simple representation of the distribution of current. Curves are shown for the two components and the magnitude of the complex effective length as functions of the length, the radius, and the orientation of the antenna in a linearly polarized electric field. Application is made to elliptically polarized fields which includes the case of ionospheric reflection. Numerical examples involving the computation of current in a loaded receiving antenna for several typical fields of different polarizations are given.