This paper presents the 5.8 GHz high sensitivity rectenna array with advanced microstrip-type rectifiers and circularly patch antennas achieving a good balance between a high-efficiency and RF weak power operation. The fabricated rectenna element has achieved RF-DC conversion efficiency of 54% at input RF power of 1mW. Furthermore, we have proposed the novel structure which enhances robustness to the breakdown of the diodes when the rectenna elements are arrayed.