Differential Beamforming

Differential beamformers have two great advantages. The first is that the corresponding beam‐patterns are almost frequency invariant, which is extremely important when one deal with broadband signals. The second is that they give the highest gains in diffuse noise. These two characteristics make differential beamforming very useful and practical in many applications. This chapter examines differential sensor arrays (DSAs) of different orders. The most well‐known and frequently studied
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th‐order DSA beampatterns are the dipole, the cardioid, the hypercardioid, and the supercardioid. The chapter shows how they are obtained. The major drawback of DSAs is white noise amplification. As the order increases, the amplification of white noise worsens. The best way to deal with this fundamental problem is to disconnect the order of the DSAs from the number of sensors and increase the latter for a fixed order.