We propose the generalised pattern search (GPS) optimisation algorithm for steering nulls in the directions of interference. This algorithm is a deterministic, fast and efficient derivative-free optimisation process searching for function minima. A new technique based on step amplitudes for excitations of array elements is used as the template. In order to reduce the complexity and cost, only the positions of selected elements of the array are optimised for suppression of narrow or wide interferences by the GPS algorithm. The results show that the GPS algorithm is an efficient and robust technique in imposing single null, multiple nulls or wide suppressed sectors by perturbating only the selected few array elements while the other elements freeze. Furthermore, the full-wave simulations of the synthesised arrays are also completed to examine the effects of mutual coupling on the radiation patterns.