An apparatus for applying RF energy to an energy application zone is disclosed. The apparatus may include: a set of receiving radiating elements, including at least first and second radiating elements sequentially interconnected. The sequential interconnection may be such that energy received by one of the receiving radiating element from the energy application zone is emitted back to the energy application zone by the next radiating element in the sequence and energy received by the last radiating element in the sequence from the energy application zone is emitted back to the energy application zone by the first radiating element in the sequence.