Dergiler / Turkish Journal of Electrical Engineering and Computer Science / 2014 / Cilt: 22 - Sayı: 2

Design, optimization, and realization of a wire antenna with a 25:1 bandwidth ratio for terrestrial communications

Sayfa
371–379
DOI
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Özet

Wire antennas can be made wideband if the antenna is loaded with passive elements and connected to a lossless matching network. However, realization of the load component values and matching network can easily become impractical. In this study, using only a surface mount and standard component values, antenna loads and a matching network are optimized using genetic algorithms. The optimized design achieves a 25:1 bandwidth ratio, from 20 MHz to 500 MHz, with a maximum voltage standing wave ratio (VSWR) of 3.5 and minimum system gain of --5 dBi. The antenna system gain at azimuth is taken as the objective function and an exact penalty function is formulated to take into account the VSWR over the design frequency band. A loaded antenna is built and measured to corroborate the simulations results. The realized antenna is only 0.14 lambda long at 20 MHz.

Abstract

Wire antennas can be made wideband if the antenna is loaded with passive elements and connected to a lossless matching network. However, realization of the load component values and matching network can easily become impractical. In this study, using only a surface mount and standard component values, antenna loads and a matching network are optimized using genetic algorithms. The optimized design achieves a 25:1 bandwidth ratio, from 20 MHz to 500 MHz, with a maximum voltage standing wave ratio (VSWR) of 3.5 and minimum system gain of --5 dBi. The antenna system gain at azimuth is taken as the objective function and an exact penalty function is formulated to take into account the VSWR over the design frequency band. A loaded antenna is built and measured to corroborate the simulations results. The realized antenna is only 0.14 lambda long at 20 MHz.

Anahtar kelimeler: Broadband antenna, loaded wire antenna, genetic algorithms, exact penalty functions