Apparatus and method for adaptively controlling array antenna comprising adaptive control means with improved initial value setting arrangement

An apparatus for adaptively controlling an array antenna comprised of a predetermined plurality of M antenna elements arranged closely to each other in a predetermined arrangement form, comprising:

• multi-beam forming means for calculating a predetermined plurality of N beam field strengths based on a plurality of M reception signals received by the antenna elements of the array antenna, directions of respective main beams of a plurality of N beams to be formed which have been predetermined so that a desired wave can be received in a predetermined radiation angle, and a reception frequency of the reception signals;
• beam selecting means for selectively outputting beam field strengths equal to or greater than a predetermined threshold value by comparing said plurality of N beam field strengths calculated by said multi-beam forming means, with the predetermined threshold value;
• and
• at least two adaptive control means for calculating a plurality of N weight coefficients for the reception signals corresponding to a plurality of N beams based on the beam field strengths outputted from said beam selecting means according to a constant modulus algorithm, respectively multiplying the calculated beam field strengths by a plurality of calculated N weight coefficients, combining,in phase respective signals of multiplication results obtained by said multiplication, and outputting the combined signal as a reception signal;
• first initial value setting means for, in a predetermined initial state of said one adaptive control means, setting a weight coefficient of one adaptive control means corresponding to the maximum beam field strength among the beam field strengths outputted from said beam selecting means to a predetermined initial value being not zero, and setting weight coefficients corresponding to the other beam field strengths to zero;
• and
• second initial value setting means for, in a predetermined initial state of said other adaptive control means, setting a weight coefficient of said other adaptive control means corresponding to at least a beam field strength having the second greater level among the beam field strengths outputted from said beam selecting means to the predetermined initial value, and setting weight coefficients corresponding to the other beam field strengths to zero.