Three-Dimensional Isotropic Power Reception Via Spherical Transmission Antenna and Linearly Polarised Receiver Antenna

A commonly invoked concept in radar and communications theory is that of a hypothetical three-dimensional (3D) omnidirectional isotropic transmission antenna for which the output radiative power depends only on the spherical radial distance from the subject antenna to a given observation point and is independent of the spherical angular coordinates. In the present investigation, a similar transmitter-receiver antenna system is developed for which the collected power of a linearly polarised receiver antenna depends only on the spherical radial distance from a specially designed transmission antenna to this receiver antenna and is independent of the spherical angular coordinates. This system design capitalises on the radiative properties of a particular spherical transmission antenna that is characterised by azimuthal rotation of the radiative fields and power pattern. This property of 3D isotropic power reception applies exactly in the near field, far field and all intermediate ranges from the spherical transmitter to the linearly polarised receiver. Likewise, this 3D isotropic receive power property is applicable for all radio frequency (RF) wavelengths, both larger and smaller than the radius of the spherical transmission antenna. This proposed antenna system concept could offer utility in multiple applications, including communications beaconing and radar surveillance.