Title :
Antennas with artificial magneto-dielectric substrates: the dominant role of frequency dispersion
Author :
Ikonen, Pekka ; Maslovski, Stanislav ; Tretyakov, Sergei
Author_Institution :
Radio Lab./SMARAD, Helsinki Univ. of Technol., Espoo
Abstract :
In this review paper we discuss the impact of frequency dispersion of artificial magneto-dielectric materials designed for antenna applications. The emphasis is on artificial substrates for microstrip antennas, used with the intention to reduce the antenna size or/and improve the impedance bandwidth characteristics. Here we compare the impedance bandwidths of miniaturized resonant antennas loaded with practically realizable, dispersive magneto-dielectric substrates and conventional high-permittivity substrates. Analytical expression is derived for the ratio between the radiation quality factors obtained using these substrates. It is shown that the ratio always exceeds unity, thus, artificial magneto-dielectric substrates offer no advantages in antenna miniaturization. This observation is experimentally validated
Keywords :
antenna radiation patterns; dielectric materials; magnetic materials; microstrip antennas; substrates; antenna size reduction; artificial magneto-dielectric substrates; conventional high-permittivity substrates; frequency dispersion; impedance bandwidth characteristics; microstrip antennas; miniaturized resonant antennas; radiation quality factors; Bandwidth; Dielectric substrates; Dispersion; Frequency; Impedance; Loaded antennas; Magnetic analysis; Magnetic materials; Magnetic resonance; Microstrip antennas;
Conference_Titel :
Antennas and Propagation Society International Symposium 2006, IEEE
Conference_Location :
Albuquerque, NM
Print_ISBN :
1-4244-0123-2
DOI :
10.1109/APS.2006.1710540
