Evaluation of Mutual Coupling Between Slots From Dipole Expressions

Abstract

Abstract-Two closed form approximations are given for mutual coupling between arbitrarily oriented slots with cosinusoidal distribution, using the known results for dipoles along with a new correction factor to account for the piecewise sinusoidal dipole current. Using these approximations, a scheme has been developed for calculating mutual coupling between practically used slots of arbitrary orientation and useful results are obtained from simple closed form expressions for slot separation of 1.2 × slot length or more depending upon the approximation chosen and the length of the slot. These approximations are found to be more accurate than those available in the literature, with a maximum error of less than 1.6% for slots shorter than 0.5 wavelength and separated by 0.85 × wavelength or more. Simple yet accurate expressions for mutual coupling, like the point dipole approximation developed here, result in efficient evaluation of mutual coupling for the design of large arrays of slots or for Electromagnetic Compatibility analysis.

Mutual Coupling in Longitudinal Arrays of Compound Slots

“…9, which represents a simplification of the model proposed in [7,12,13] since the slots are always parallel to each other. The centre of the slot 1 is placed at the origin of the coordinate system zy at (0, 0, 0) and its length is 2l 1 .…”

“…The width w is the same for both slots and much less than length to keep the condition of narrow slot, w 10 < 2l. The formulation presented in [12] is followed to calculate the mutual coupling factor as…”

Analysis of a Rectangular Waveguide Fed Compound Slot by Image Method

“…Because of all these advantages, the compound slots have also been analysed using the image method in this paper. The mutual admittance for the nearest slots has been evaluated using the single dipole or the double dipole approximation whereas the farther admittances have been evaluated using the simpler point dipole approximation [20,21]. The θ-algorithm has been used for convergence acceleration of the summation of image admittances, and the effect of various algorithms on the convergence of resonant length with respect to the number of images has been studied.…”

Combined Vibrator-Slot Structures in Electrodynamic Volumes

“…Therefore, to find the solution of the coupled Equations (18), we will use the generalized method of induced EMMF, with approximate expressions for the currents J v (s 1 ) = J 0v f v (s 1 ) and J sl (s 2 ) = J 0sl f sl (s 2 ) (here J 0v and J 0sl are treated as unknown amplitudes), previously obtained by solving Equations (19) by the averaging method. So, we multiply Equation (18a) by the function f v (s 1 ) and Equation (18b) by the function f sl (s 2 ) and integrate Equation (18a) over the vibrator length and Equation (18b) over the slot length.…”

“…It may be explained by further development of modern antenna techniques and antenna-feeder devices which can be characterized by such features as multielement structures, integration and modification of structural units to minimize their mass and dimensions and to ensure electromagnetic compatibility of radio aids, application of metamaterials, formation of required spatial-energy and spatial-polarization distributions of electromagnetic fields in various nondissipative and dissipative media. To solve these tasks electric and magnetic radiators, based on various impedance structures with irregular geometric or electrophysical parameters, and on combined vibrator-slot structures, should be created [12][13][14][15][16][17][18][19][20].…”