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A three-way power divider based on Bagley polygon is here reduced in dimension by applying the concept of reducing delay line length by applying open circuit stubs. Whereas this technique is known in literature, the delay line reduction is done symmetrically by placing the stub mid-line, which would imply packing issues leading to a reduced size reduction. In this contribution a theoretical development on non-symmetric reduced length delay line is carried out, allowing for a more effective size reduction of the Bagley-based power divider. Measurements on a prototype designed at 2.45 GHz occupying less than half of the area of a canonical Bagley divider with comparable performances over a slightly reduced operational bandwidth prove the validity of the approach. [ABSTRACT FROM AUTHOR]

The identify friend or foe antenna is a complement to many radar antennas which allows the discrimination between friendly and hostile targets by receiving identification data. Such antenna must synthesize both a sum and a difference pattern in azimuth to allow target discrimination and must point to the target being inquired, either by mechanical or electronic scanning in azimuth. In this paper, to attain optimal electronic scanning, an array of antennas lying on a generic planar curve is considered. A multi-objective optimization based on the invasive weed optimization algorithm is then applied to the shape of such curve, aimed at maximizing performances. Whereas a conventional linear array of 6 elements can effectively scan ±30°, with respect to broadside, the proposed array, notwithstanding the same number of elements and overall length, can scan ±45° and still synthesize effective sum and difference patterns. [ABSTRACT FROM AUTHOR]

An elementary dipole in presence of a perfectly conducting wedge radiates a field whose analytic expression can be written in terms of a double infinite series. A dipole located at a point characterized by complex coordinates behaves in the real space as a directive source akin to a Gaussian beam in the paraxial region. In this article, the series solution, originally conceived for a dipole located at a point characterized by real coordinates, is extended to the case of a complex coordinates source, hence providing an analytical solution approximating the problem of a wedge illuminated by a Gaussian beam. [ABSTRACT FROM AUTHOR]

In this paper an antenna array operating in circular polarization in the C-band is presented. The array is based on the sequential rotation architecture, applied to six elements, and arranged in hexagonal shape. Thanks to its geometry, the array is suitable for tiling of surfaces as well as for regular solid arrangement. Satisfying experimental validation of a prototype based on the proposed design is observed, with a peak gain of 10.4 dB at 5.8 GHz maintained within 3 dB over a 500 MHz band, a 10 dB return loss bandwidth of 500 MHz, and a 3dB axial ratio bandwidth of almost 400 MHz, meaning 6.5% of fractional bandwidth. [ABSTRACT FROM AUTHOR]

This paper describes the design and experimental characterization of a circular polarized printed antenna for dual-band WiFi operation at 2.45 GHz and 5.10 GHz. The patch design is based on a combination of slits loading and gap-coupling applied to a disc patch in order to enhance the radiation performances in terms of polarization purity and bandwidth at the two operation frequencies. Experimental validations confirm a maximum gain around 6.0 dB for both 2.45and 5.10 GHz, as well as an axial ratio as low as 0.5 dB and a return loss exceeding 15 dB on the operating frequencies. These characteristics are suitable for operationing in IEEE802.11x networks. [ABSTRACT FROM AUTHOR]