Electromagnetism

Dielectric Frequency Selective Surfaces
	Description Dielectric Frequency Selective Surface: novel modified dielectric frequency selective surfaces (MDFSS) have been analyzed under 3-D plane wave incidence. Unlike classic DFSS, this MDFSS can easily be developed. The electromagnetic analysis is carried out using the Multimode Equivalent Network (MEN) approach. Results have shown that MDFSS ensure total reflection with a larger bandwidth than the classic DFSS for normal incidence. Bandwidth can be enlarged and modified by doubling the MDFSS. Similarly, two MDFSS can be combined to ensure total reflection for elliptically polarized wave incidence. A dielectric stop band filter with enlarged bandwidth can be obtained by cascading several MDFSS. Unfortunately, the frequency behavior of the cascade is influenced by , the angle of incidence of the impinging plane wave. In fact, if the stop band filter is developed at f0 for normal incidence, not only does it not maintain the same bandwidth for  ≠0° but it also moves its central frequency toward other values with lower bandwidth and loses its stop band characteristic in a range of a few angles. This effect, known as angular stability, can be mitigated by cascading MDFSSs resonating at different angles of incidence. In this case, the choice of the MDFSSs plays an important role and it can be shown that the required relative bandwidth can be maintained in the angular range 0-30°.
	Contact Person: Leonardo Zappelli
	People: Leonardo Zappelli