A Leay Wave Antenna With Dielectric Superstrate on Perforated Dielectric Spacer

In this article, a leay wave antenna with dielectric superstrate (LWADS) on the perforated dielectric spacer is proposed. The LWADS has an asymmetric structure with a half-filled dielectric spacer and with a nonfilled spacer to make a quasi-cutoff region. The half-filled dielectric spacer is periodically perforated, and the beam direction of the leaky wave is controlled by changing the hole radius. In general, the unwanted radiation occurs in the broadside direction when the beam of the leaky wave is tilted at a large angle, and this unwanted radiation is avoided by providing these perforated dielectric spacers. The proposed design is validated by measurements at X-band, and it is shown that a high gain tilted beam pattern with peak gains of 14 dBi is obtained not only at
$\theta =20^{\circ }$
and 40° but also at the wide-angle of
$\theta =60^{\circ }$
. Since the effective permittivity can be controlled by the hole radius, an array of LWADS with different beam angles can be realized with the same height and a multibeam antenna with switched feeding can be realized.