New DBS receiver antennas

High gain and low noise characteristics are strongly required for DBS receiving antennas; reflector antennas have been the most popular. Recently, various kinds of flat array antennas are proposed and used as commercial products. This paper describes the state of the art of DBS receiving flat arrays. Firstly, comparative studies of various arrays in commercial use are performed to demonstrate the effects of feeding loss upon the antenna efficiency. It includes classical arrays composed of microstrip, triplate and suspended lines as well as novel slotted waveguide arrays which are highlighted in this talk. In the next place, remarkable efficiency of a radial line slot antenna (RLSA) of more than 85% is reported. Theoretical design method is also surveyed. Radial waveguide arrays with different elements are also introduced. Finally, slotted waveguide arrays for wider applications are summarized. It includes (1) Parallel plate waveguide arrays, (2) Leaky wave slotted waveguide arrays with 50 tilted beam for mobile DBS reception and (3) wideband and slim base station antennas for mobile communication. The unique concepts as well as promising characteristics are presented.