Ryuji Kuse

Variable reflection angle meta-surface using double layered patch type FSS

This paper proposes the variable reflection angle meta-surface using the double layered structure which can change the scatter pattern simply by sifting other layer. It is clarified that the gradients of the element vs. the reflection phase are changed by the relative position between two layers in double layered patch type FSS (Frequency Selective Surface). It is found that the reflection angle with range of about -34 deg. to -2 deg. is obtained in the proposed meta-surface.

Equivalent circuit analysis for double layer patch type AMC in consideration of mutual coupling between layers

This paper describes the equivalent circuit analysis of a double layer AMC (Artificial Magnetic Conductor) in consideration of mutual coupling between layers. The AMC with double layer patch type FSS (Frequency Selective Surface) is focused. This paper treats two type double layer structures. The one is stacked structure, and the other is alternated structure. It was shown that the calculated results by using the equivalent circuit well agreed with the results of the FDTD analysis. In addition, it was clarified that the stacked and alternated structures cause the common mode and the differential mode coupling, respectively. Moreover, it was shown that the miniaturization of the AMC is designed by setting the distance between the layers of double layer FSS as thin as possible.

Filtering characteristics of FSS for realizing perfect magnetic conductor without frequency dependence

This paper focuses on an AMC (Artificial Magnetic Conductor) composed of a FSS (Frequency Selective Surface) and the ground plane, and describes the ideal filtering characteristics for realizing PMC (Perfect Magnetic Conductor) which is independent of frequency. The ideal filtering characteristics is derived from the condition for realizing the PMC in all the frequency using the relational expression between the filtering characteristics of a FSS and the PMC characteristics of the AMC. As the result, it is clarified that the ideal filter is a band pass filter. It is also shown that the optimum distance h between a FSS and the ground plane is a quarter wavelengths at the band pass frequency. On the other hand, it is found that the phase rotation direction is opposite compared with the conventional band pass frequency. It is found that the ideal filtering characteristics can be realized by using negative index material.

Frequency bandwidth of patch type meta-surface with polarization conversion function

A meta-surface can reflect the incident wave with arbitrary reflection coefficient. This paper proposes a novel meta-surface which has polarization conversion function. A linearly polarized (LP) incident wave can be converted to a circularly polarized (CP) reflected wave by using a rectangular patches and the ground plane. In addition, the relationship between the frequency bandwidth and the structure are clarified. The maximum value of the frequency bandwidth is converged to approximately 87%.

Equivalent circuit analysis for AMC with double layer patch type FSS

This paper describes the possibility of the miniaturized AMC (Artificial Magnetic Conductor) by the equivalent circuit analysis. The AMC with double layer patch type FSS (Frequency selective surface) is focused as the structure of AMC. It is clarified by the theoretical results that the operation frequency of the FSS becomes the half by using double layer patch type FSS. It is also shown that unit cell size of an AMC is miniaturized by the half.

Horizontally polarized omni-directional antenna using orthogonal polarization conversion FSS

This paper proposes the horizontally polarized omni-directional antenna with a cylindrical frequency selective surface (FSS). The FSS features the orthogonal polarization conversion function. Therefore, the vertically polarized wave radiated from a dipole antenna is converted to the horizontally polarized transmitted one. The simulation results by using the FDTD and the MoM show that this antenna has the good performance as the horizontally polarized omni-directional antenna.

Spatial filter by using multilayered FSS for orthogonal polarization conversion

This paper proposes the spatial filter with FSS(Frequency Selective Surface) for orthogonal polarization conversion such as converting the vertical polarization to horizontal polarization. It is found that multilayered loop-slot type FSS having band-pass filter characteristics realize orthogonal polarization conversion. Furthermore, it is shown that the optimal number of layers of the FSS is three, and maximum value of relative bandwidth is 9.5%.

Variable Reflection Angle Meta-surface using Double Layered FSS

This paper proposes the variable reflection angle meta-surface composed of the double layered FSS (Frequency Selective Surface) and the ground. The meta-surface can steer the reflection direction of the incident wave by shifting the lower FSS. It is clarified that the gradient of the reflection phase in the reflection direction steering plane (x-z plane) are changed by the shift amount of lower FSS. It is found that the reflection direction of the normal incident wave is obtained up to at 45 degrees by using the proposed meta-surface.

Variable reflection angle meta-surface for orthogonally polarized waves

This paper proposes a variable reflection angle meta-surface using double layered FSS (Frequency Selective Surface) for orthogonally polarized waves which can change the scattering pattern easily by shifting one layer. The reflection angle within range of about -20 deg. to -5 deg. is obtained in case of orthogonally polarized waves.

Equivalent circuit analysis for alternated double layer patch type FSS with dielectric substrate

This paper describes the filtering characteristics of the alternated double layer patch type FSS (Frequency Selective Surface) in which a patch type FSS is arranged alternately at the surface and the back of a dielectric substrate. The equivalent circuit and the empirical equation of the coupling coefficient including dielectric substrate effect are proposed. It is also shown that the approximate equation is valid when the thickness of the dielectric substrate t/p less than 0.5.