Design and development of electronic beam switching antenna for point-to-multi-point long range data link applications

Design and Development of broad band, Electronic Beam Switching Antenna for Omni directional coverage in L-Band is presented. The U4 monopoles and helices are good candidatures for wide coverage application like on-board applications, but suffer with low gain. Electronic beam switching antenna (EBSA) arrays can give required high gain and time-slotted omni-directional coverage in long range datalink for ground to air missile and UAV applications. It reduces transmitter power requirement for ground as well as on-board segment. It indirectly, reduces interference and multipath. EBSA contains 8 sector antennas satisfies the required 3dB beamwidth of ±22.50 in Az plane and ±100 in El plane with 14dBic on axis gain with RHCP for covering higher slant ranges and near horizon coverage. Near ranges and over-head coverage is provided with linear polarized printed dipole antenna that satisfies the required 3dB beam width of ±370 and 10dB beamwidth of ±700 in both Az and El planes with -5.5 dBiL minimum gain at cross-over point of sector and zenith. The beam switching is achieved by antenna switching unit with appropriate built-in tests. Realized sector antenna has shown VSWR ≤ 2, Axial Ratio of better than 2dB on axis and better than 4dB around 3dB zone.