Development of tripole and multipole antennas
Scientists of Tallinn University of Technology develop mathematics of tripole and multipole antennas
Prussian Academy announced in 1879 an open competition who first shows the existence or non-existence of EM waves predicted 15 years earlier by the mathematical theory of James Clerk Maxwell. The competition was won in 1882 by young Heinrich Hertz in favour of Maxwell’s theory. He did this by constructing a dipole antenna radiating EM waves which he could measure. It is needless to mention the importance which this experiment together with Maxwell’s theory has had for modern society. Hertz’s antenna consisted of two identical perfectly con- ducting planar bodies, in his case squares which create radiating EM waves. Since, by reciprocity, the radiating antennas are identical to receiving antennas, the theory of antennas is closely connected to EM scattering and inverse scattering theory.
We plan to introduce more general antennas. Our aim is to replace dipole-antennas by tripole (see the illustration) or multipole antennas. This is the first paradigm change after after Maxwell-Hertz theory from the late 1900 -century. We believe corner singularities with simple geometric self-similarity are the key to frequency independent basic characteristics like impedance and beam form of the antennas: find such an antenna shape that the antenna feed impedance is constant over a large frequency range. This self-similarity leads to a self-similarity of the current distribution in the antennas, which in turn can be used to design antennas of frequency-independent charateristics like antenna beam pattern and feed impedance.
Currently the study is focused on development of mathematical theory of these antennas in context with direct and inverse scattering of electromagnetic waves.
Contact: Prof. Lassi Päivärinta, Department of Cybernetics, Tallinn University of Technology, Ehitajate tee 5, 19086 Tallinn, Estonia. E-mail: lassi.paivarinta (at) taltech.ee