Design and Experimental Verification of a Compact Gaussian Beam Source for Parallel-Plate Waveguide Tests

We present a compact and efficient electromagnetic source able to generate a 2-D Gaussian beam in a parallel-plate waveguide. The parallel-plate waveguide is a typical guiding structure used to experimentally test in a laboratory the electromagnetic behavior of a device under test in terms of propagation, transmission, and reflection. The most common launcher for this waveguide is a quarter-wavelength monopole, which generates a cylindrical wave. However, in order to approximate the cylindrical wave to a plane-wave impinging on the device under test, this launcher needs electrically large setups. The proposed solution makes use of a metallic bidimensional parabolic reflector, which is able to transform the cylindrical wave radiated by the conventional launcher into a plane wave with the Gaussian amplitude distribution. We demonstrate that this setup can dramatically reduce the dimensions of a conventional launcher for a given directivity (i.e., planarity of the generated phase fronts). The optimum design and the experimental verification of the proposed compact launcher are presented.

[1]  Andrea Alù,et al.  Mantle cloaking for co-site radio-frequency antennas , 2016 .

[2]  F. Bilotti,et al.  Antenna Arrays Emulate Metamaterial-Based Carpet Cloak Over a Wide Angular and Frequency Bandwidth , 2018, IEEE Transactions on Antennas and Propagation.

[3]  George V. Eleftheriades,et al.  Experimental Demonstration of Active Electromagnetic Cloaking , 2013 .

[4]  Andrea Alù,et al.  Terahertz carpet cloak based on a ring resonator metasurface , 2015 .

[5]  S A Tretyakov,et al.  Functional metamirrors using bianisotropic elements. , 2015, Physical review letters.

[6]  A.P. King,et al.  The Radiation Characteristics of Conical Horn Antennas , 1950, Proceedings of the IRE.

[7]  John L. Volakis,et al.  Antenna Engineering Handbook , 2007 .

[8]  Zhongxiang Shen,et al.  Wideband Flush-Mounted Surface Wave Antenna of Very Low Profile , 2015, IEEE Transactions on Antennas and Propagation.

[9]  F. Bilotti,et al.  Antenna-based carpet cloak: A possible frequency and angular broadband cloaking technique , 2016, 2016 10th International Congress on Advanced Electromagnetic Materials in Microwaves and Optics (METAMATERIALS).

[10]  S. Tretyakov,et al.  A microwave transmission-line network guiding electromagnetic fields through a dense array of metallic objects , 2008, 0805.4055.

[11]  David R. Smith,et al.  Spatial mapping of the internal and external electromagnetic fields of negative index metamaterials. , 2006, Optics express.

[12]  David R. Smith,et al.  Metamaterial Electromagnetic Cloak at Microwave Frequencies , 2006, Science.

[13]  Psang Dain Lin,et al.  Optimized variable-focus-parabolic-trough reflector for solar thermal concentrator system , 2012 .

[14]  Henry Jasik,et al.  Antenna engineering handbook , 1961 .