Designing a wideband spatial beamformer for low sidelobe radiation pattern performance

This paper presents a wideband spatial beamformer which is able to steer beam in azimuth over a wide frequency band without the use of phase shifters, frequency filters or delay networks. The required weights at individual antenna elements are represented by real numbers which in practice can be realized by amplifiers or attenuators. The described beamforming scheme works for an arbitrary size array. However, its performance is affected by mutual coupling between the array elements which leads to increasing sidelobe levels. In order to counter count this effect a Chebyshev synthesis method for radiation pattern with low side lobes is applied. This method avoids the mutual coupling compensation technique which would require the use of complex weighting coefficients.