Naslov
Some new results on stacked butterfly and circular patch antennas

Autori
Zentner, Radovan ; Bonefačić, Davor ; Bartolić, Juraj

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
Proceedings of the Progress In Electromagnetics Research Symposium / NN - : Schlumberger-Doll Research, 1997, 854-854

Skup
Progress In Electromagnetics Research Symposium

Mjesto i datum
Cambridge (MA), Sjedinjene Američke Države, 07.07.1997. - 11.07.1997

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
patch antenna; stacked patch antenna; impedance matching

Sažetak
In order to increase the operating bandwidth of microstrip antennas adding a parasitic element over a driven patch has been considered. Butterfly and circular inverted stacked patch configurations have been investigated. The parasitic patch was printed on a dielectric slab, acting as a radome. For both configurations the microstrip line excitation is used. Using a MoM based computer simulation of stacked butterfly patches, the optimal antenna layout was found and the air gap height between driven and parasitic patch was optimized to achieve an input impedance locus suitable for matching. The butterfly patch antenna is linear polarized and after matching a bandwidth of 24 percent with VSWR less than 2 has been obtained. The influence of the air gap height on input impedance of circular stacked patches has been experimentally investigated. The air gap height, optimal for input impedance matching in a wider frequency band has been determined. After matching, the achieved bandwidth of the circular stacked patch antenna was 18 percent with VSWR less than 2. The circular patch configuration has a smaller bandwidth, but can be used for both linear and circular polarizations. Furthermore, it is less sensitive on the position where the microstrip excitation line is connected to the driven patch, resulting in better suppression of unwanted modes produced by eventual excitation unsymmetries. Both configurations show good radiation properties with gains of about 8 dB and low cross polarization levels (bellow -19 dB). In order to match these antennas, a line transformer matching network was applied. The lengths and characteristic impedances of the line transformers were computed by using an optimizing procedure from a prescribed VSWR and measured antenna impedance data within the whole bandwidth of interest.

Izvorni jezik
Engleski

Znanstvena područja
Elektrotehnika

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