On bounds of the Q-factor as a function of array antenna directivity

• In this paper we determine the trade-off between the Q-factor and partial (super) directivity for linear arrays of dipoles. The dipoles are densely spaced in a one or two wavelength long array. We compare the bound for port-feed dipoles with the current optimization approach, with optimal currents on the whole dipole area, and also with an enclosing plate. It is interesting to note that port-feed dipoles are close to the optimal current dipoles in the endfire case, for sufficiently many dipoles in the array, for a wide range of directivities. We also show that the optimization problem for the 'optimal current' and 'the port-feed' cases are very similar and that the Pareto-front (trade-off curve) can be obtained and compared for the different cases.

Subject headings

TEKNIK OCH TEKNOLOGIER  -- Elektroteknik och elektronik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Electrical Engineering, Electronic Engineering, Information Engineering (hsv//eng)

Keyword

Array antenna

Bandwidth

Current optimziation

Physical bound

Q-factor

Superdirec-tivity

Antenna feeders

Curve fitting

Economic and social effects

Q factor measurement

Array antennas

Current optimization

Optimal current

Optimization problems

Q-factors

Trade-off curves

Antenna arrays

Publication and Content Type

ref (subject category)

kon (subject category)