A New Approach to the Mutual Immittance between Two Radiators

Abstract

Variational expression for mutual immittance between two radiators of arbitrary shapes excited by electric current, magnetic current or their combination is derived. The evaluation of the integral representing the mutual reaction between two radiators gets considerably simplified by representing it in terms of angular spectrum of plane waves. An expression for mutual immittance is derived on dividing the mutual reaction either by the product of currents at the feed points of radiators when the radiators are in the form of dipoles, or by the product of reference voltages when the radiators are in the form of apertures. The reference voltage is the dominant mode voltage of waveguide having same dimensions as the aperture. The slots in an infinite ground plane are studied as limiting case of the apertures.

The formulation is used to compute the mutual impedance of two parallel half-wave dipoles as a function of spacing (0 ⩽ D/λ ⩽ 0.5) between them. The results are compared with those given by Jordan. The formulation is also extended to the case of two inclined dipoles and slots.

Indexing Terms:

• Dipole Radiators
• Mutual Immittance
• Plane Wave Spectrum