초록 ▼

An artificial anisotropic dielectric material is used as a microstrip patch antenna substrate and can achieve dramatic antenna weight reduction. The artificial dielectric is comprised of a periodic structure of low and high permittivity layers. The net effective dielectric constant in the plane para

An artificial anisotropic dielectric material is used as a microstrip patch antenna substrate and can achieve dramatic antenna weight reduction. The artificial dielectric is comprised of a periodic structure of low and high permittivity layers. The net effective dielectric constant in the plane parallel to the layers is engineered to be any desired value between the permittivities of the constituent layers. These layers are oriented vertically below the patch to support electric fields consistent with desired resonant modes. Substrates may be engineered for both linearly and circularly polarized patch antennas. Substrate weights can be reduced by factors of from 6 to 30 times using different types of high permittivity layers. This concept has numerous applications in electrically small and lightweight antenna elements, as well as in resonators, microwave lenses, and other electromagnetic devices.

대표청구항 ▼

[ What is claimed is:] [1.] An artificial dielectric structure comprising:first and second stacked dielectric layers having first and second permittivities, respectively, said first permittivity being different from said second permittivity,wherein said artificial dielectric structure has a permitti

[ What is claimed is:] [1.] An artificial dielectric structure comprising:first and second stacked dielectric layers having first and second permittivities, respectively, said first permittivity being different from said second permittivity,wherein said artificial dielectric structure has a permittivity tensor comprised of permittivity components respectively defined along three principal axes, one of said permittivity components along a certain axis of said principal axes being substantially different than both of the other two of said permittivity components,and wherein said dielectric layers each have substantially parallel top and bottom surfaces and are stacked in a first direction perpendicular to said top and bottom surfaces such that said top surface of said first dielectric layer is adjacent to said bottom surface of said second dielectric layer, said certain axis being parallel to said first direction,and wherein said other two of said permittivity components are greater than said one permittivity component along said certain axis by at least a factor of 5,and wherein said first and second dielectric layers have first and second thicknesses t.sub.1 and t.sub.2, and first and second permittivities .epsilon..sub.r1 and .epsilon..sub.r2 respectively, said first and second thicknesses satisfying the condition that t.sub.n <<1/.beta..sub.n, where .beta..sub.n =.omega..times.sqrt(.mu..sub.0 .epsilon..sub.0 .epsilon..sub.rn) for n=1,2, and .omega.=2.pi.f where f is the maximum operating frequency of said artificial dielectric structure.