Beam Forming with Nonsinusoidal Coded Waveforms

The principle of beam forming based on a line array of sensors for nonsinusoidal signals with rectangular time variations is advanced to include beam forming of coded nonsinusoidal signals. The energy patterns of coded waveforms using complementary codes have a narrow main beam for small angles of incidence, a large number of sidelobes forming minor beams for large angles of incidence, and a constant value of 1/N, where Nis the number of sensors in the line array. Arrays with a large number of sensors N ¿ 64 have array gains that reduce the large amplitudes of the sidelobes significantly, eliminate the sidelobes with small amplitude, and decrease the final value to 1/N. The resolution angle e can be reduced by increasing the array length L or by increasing the bandwidth ¿f = 1/2T, where T is the nominal pulse duration of the coded waveform.