Apparatus for controlling array antenna comprising a plurality of antenna elements and method therefor

An apparatus for controlling an array antenna including a predetermined plurality of M antenna elements arranged closely to one another in a predetermined arrangement configuration, said apparatus comprising:

• multi-beam forming means for calculating beam electric field strengths of a plurality of N beams of transmitting signals, based on a receiving frequency of receiving signals, a plurality of M receiving signals respectively received by said antenna elements of said array antenna, and directions of predetermined plurality of N beams of transmitting signals to be formed, said directions having been predetermined so that a desired radio wave can be received in a predetermined range of radiation angle;
• beam selecting means for comparing said plurality of N beam electric field strengths calculated by the multi-beam forming means with a predetermined threshold value, and selectively outputting signals representing said beam electric field strengths equal to or larger than said threshold value;
• adaptive controlling means, based on said signals representing said beam electric field strengths outputted from said beam selecting means, for calculating a plurality of N weight coefficients for the receiving signals respectively corresponding to the plurality of N beams of transmitting signals, said weight coefficients being calculated such that a main beam of the array antenna is directed toward an incoming direction of a desired radio wave and also a level of said receiving signal in an incoming direction of an unnecessary radio wave are made zero;
• calculating means, based on said plurality of N weight coefficients calculated by said adaptive controlling means and a transmitting frequency of the transmitting signals, for calculating at least either one of a plurality of M amounts of phase shift and a plurality of M amounts of amplitude for the transmitting signals, respectively corresponding to said antenna elements, such that the main beam of the array antenna is directed toward the incoming direction of the desired radio wave and also the level of the transmitting signal in the incoming direction of the unnecessary radio wave are made zero;
• and
• antenna controlling means for controlling said antenna elements of said array antenna, respectively, in accordance with at least one of said plurality of M amounts of phase shift calculated by said calculating means and said plurality of M amounts of amplitude calculated by said calculating means, thereby radiating the controlled transmitting signals from said antenna elements of said array antenna.