The ultra-low sidelobe dipole array of 16-elements

The wideband technique to compensate the mutual coupling in a small array is developed and experimentally verified. According to this novel compensative method, a collinear and a parallel dipole array of 16 elements with -50dB sidelobe level are computed. For a collinear dipole array, numerical results indicate that the sidelobe level is greater than -46.5dB within 15% bandwidth and the optimal sidelobe is -48.5dB, For a parallel dipole array the sidelobe level is from 45.4dB to -47.8dB within 15% bandwidth. This paper also discusses error tolerance across a constrained-fed array antenna. A method, in which the different exciting currents have different error tolerance, is adopted and this allows a better error tolerance for a practical ultra-low sidelobe array antenna. Using the above method, the L-band constrained-fed collinear dipole array and parallel dipole array of 16-elements are fabricated and tested. The sidelobe level is maintained below -40dB within 13% and 12% bandwith respectively.