A.V. Ashikhmin, V.V. Negrobov, Yu.G. Pasternak, S.M. Fedorov
In this paper the various options of ultra-wideband multibeam antenna designs with the possibility of switching scan on azimuthal coordinate, based on using beam forming circuits constructed with use of modifications of plane Luneberg lens, are researched.
The structures of the lens with form of set of concentric rings (made of metal or polystyrene) with thickness which changing from center to edge of lens, are observed. Also examined the structure with form of system of circular or sectorial holes, size and frequency positioning of which are changed in radial directions from the lens center to its edges. This structure is easy for realization by use the technology of laser cutting.
Beam forming circuit placed between small bases of two truncated metal cones. Height of antenna systems is 212 mm, height of each cone is 100 mm, diameter of larger base of cone 500 mm, diameter of smaller base 300 mm, height of concentric rings of the lens structure 4 mm. It was found that the researched antenna systems are characterized by gain of about 12.8 dB at frequency range from 1 to 3 GHz.
To reduce the size of posterior lobe was offered to perform the cone as set of noncontiguous with each petal. By commuting of part of petals to the lens base, you can achieve significant reduction of posterior lobe and increasing of gain at lower part of researching range at 1-3 dB.