High-frequency diffraction contribution by planar metallic–DNG metamaterial junctions

Abstract

The plane wave diffraction by a planar junction consisting of a thick metallic sheet and a lossy double-negative metamaterial slab is studied by using the Uniform Asymptotic Physical Optics approach. This approach assumes the radiation integral as a starting point and uses the physical optics surface currents as sources to be integrated. The integral is manipulated by taking advantage of useful approximations and evaluations, and re-formulated in order to apply an asymptotic procedure able to generate a closed-form approximate solution in the framework of the Uniform Geometrical Theory of Diffraction. Accordingly, advantages and drawbacks result from the application of the proposed solution. The jumps of the geometrical optics field are compensated. Implementation and handling of the computer code are facilitated by the evaluation of well-known functions and parameters. No differential/integral equations or special functions must be computed.

Diffraction of Plane Waves by Arbitrary-Angled Coated Wedges

“…This last point is strictly related to the PO approximation and limits the evaluation of the scattered field at the beginning of the UAPO approach. It is authors' opinion that the inclusion of further wave contributions can improve the formulation of the equivalent surface currents to be used also in the shadow region, but this means abandoning the simplicity of the PO approximation and probably preventing the determination of a UTD-like solution in closed form as in [19][20][21][22][23][24][25][26][27][28][29][30][31].…”

“…The research team has denoted it as Uniform Asymptotic Physical Optics (UAPO) approach since it is based on the PO approximation of electric and magnetic equivalent surface currents radiating in the surrounding region. References [19][20][21][22][23][24][25][26][27][28][29][30][31] provide the UAPO solutions to some diffraction problems. Pros and cons of such solutions have been identified and highlighted in these manuscripts.…”

Scattering from a 90° Metallic Wedge with One Face Coated by a Double Negative Metamaterial Layer

“…According to [18][19][20][21][22][23][24][25][26][27][28][29][30], the UAPO approach allows one to isolate the high-frequency diffraction contribution that is enclosed in (6). This is possible by performing useful analytic approximations and integral evaluations.…”

“…The well-known limitations of the PO-based techniques and the absence of the surface waves in the UAPO approach can decrease the accuracy of the estimated field values in particular cases, e.g., incidence directions close to the grazing one [18]. Other canonical problems solved by means of the UAPO approach can be found in [19][20][21][22][23][24][25][26][27][28][29][30].…”

The UAPO Solution for the Plane Wave Diffraction by a Resistive Half Plane: Validation Tests

“…Unfortunately, two-dimensional propagation models have limited applications, and then diffraction problems need to be investigated when involving arbitrarily polarized electric fields at skew incidence with respect to the junction. Accounting for the features of the UAPO approach (see also [2][3][4][5][6][7][8][9][10][11] for a nonexhaustive list of references), the plane wave diffraction by an isolated resistive half plane must be first studied. Accordingly, the UAPO approach has been recently proposed for evaluating the diffracted field due to an arbitrarily polarized plane wave at skew incidence with respect to the edge of a resistive half plane [12].…”