Broadband, dual polarised microstrip antennas with improved beam forming and gain capabilities

An investigation into three-layers broadband, dual polarised and proximity-coupled microstrip antennas with improved beam forming and gain capabilities for direct-to-home (DTH) satellite reception has been carried out. The desired improvements were achieved by inserting, on an additional substrate, four square shaped elements which are electromagnetically coupled to the dual polarised main antenna element on a lower substrate. The level of the radiation pattern is less than -12 dB compared to -5 dB at the boundary angle 40/spl deg/ of a 65 cm parabolic reflector. Besides, the maximal gain of configuration BEAM has been increased more than 3 dB up to 10.03 dB. More work is still in progress to improve the connection between SMA connectors and striplines in order to measure the gain and the radiation pattern of configuration BEAMSLOT.