An effective reflector results in minimal signals behind the array. Thus additional reflector elements placed be- hind the first reflector receive only a very small residual signal going past the reflector element and therefore contribute little to the signal leaving at the front of the array. Occasionally, a multielement reflector structure can be found, but this is ready just a different geometry at the approximate distance of the primary reflector. Sometimes a plane reflector is used behind the driven element for better front-to-back performance.