A new method of broadband constant beamwidth beamforming for arbitrary geometry arrays

A new method of broadband constant beamwidth beamforming for arbitrary ge- ometry arrays is proposed. In this method, the response vector of an arbitrary geometry array is expanded into the form of sum of an infinite series, whose core function is the first kind Bessel function. The high terms of this series are truncated so that the array response vec- tors at different frequencies can be transformed to a reference frequency and then the constant beamwidth beamforming vectors are ready to obtain. With these beamforming vectors, beams at different frequencies are same as the reference beam. A reference beam optimizing method based on adaptive processing is also proposed to optimize the reference beam of arbitrary ge- ometry arrays. Computer simulation for a uniform circular array verified the effectiveness of the new method proposed.