Side-Lobe Suppression Techniques for a Uniform Circular Array

This paper provides a comparison between two different techniques for the array pattern side-lobe reduction in a passive radar system based on a circular array. The first method retrieves the phase modes pattern for the reference array and then applies a conventional tapering for the side lobe suppression of the obtained virtual uniform linear array. The second approach foresees instead an optimization algorithm in order to obtain the desired level of the side lobes. Both techniques have been adapted for being used with an 8 elements FM-based circular array for passive radar applications developed at TNO - Defence, Security and Safety in The Hague. The effect of the directional elements has been also considered for the array pattern synthesis. The different advantages of the algorithms are described and a distinction about the possible fields of application is retrieved.