Realization of desired shaped beam array of helical antennas

This paper presents an amplitude control method of Woodward synthesis technique to find out the required amplitude distribution to realize complicated shaped beams like ramp and stair-step patterns over desired angular sectors. A linear antenna array of helical antennas is modeled using CST Microwave studio for the generation of desired shaped beams like ramp and stair-step patterns. An eight element linear array of helical antennas is fabricated and its radiation patterns are measured by exciting with amplitude coefficients generated using Woodward synthesis technique by keeping the phase of the elements constant. It is observed from the results amplitude control method considered in the present paper becomes exact for larger arrays and there exists a deviation from the desired shape from small arrays. The designed data obtained for the generation of required shaped beams is highly useful for modern radar applications and point to point communications.