3D surveillance radar with distributed phased array architecture requires different Tx and Rx beams to meet the Radar's vertical coverage requirement. In typical distributed array of MxN elements, elements are arranged into M number of rows with each row having N elements and each row of N elements are fed with a single high power Transmitter module through RF power division network. While it is advantageous to have multiple narrow beams in receive to do elevation coverage, it is better to have a single wide beam in transmit due to azimuth scan timing constraints. In such type of applications, the efficient beam forming technique can be used for same antenna to create broader beam on transmit and narrow switchable beams on receive without increasing the complexity and RF distribution losses. In this paper, the application of one of the phase only techniques "Quadratic phase weighting technique" is validated for a phased array antenna used in L band surveillance radars. This paper brings out the comparison between results of MATLAB modeled algorithm with EM simulation of hardware implemented in CST. This result gives insights of implementation aspects of phase only technique for Tx beam spoiling.