[TowerTalk] a shortwave antenna with a steerable horizontal pattern

[wghsend at sohu.com]

Ladies and Gents,
  i want to design a shortwave antenna with a steerable horizontal pattern, i cann't obtain any information for this project. i want to use electrically steerable phase shifter and four linear array to relaize it,do you think it is possible? if can ,where i can find some advice about electrically steerable phase shifter.Analog phase shifters and Digital phase shifters,which one is better for my project? Please e-mail me direct.
 
Wang
wghsend at sohu.com