  RF energy harvesting (RFEH) is a promising technology for energy requirements
of wireless communication nodes. However, providing sufficient amount of energy
to ensure self-sufficient devices based on RFEH may be challenging. In this
paper, the use of diversity combining in RFEH systems is proposed to increase
the amount of harvested energy. The power consumption of diversity combining
process is also taken into account to analyze the net benefit of diversity
combining. Performances of RFEH systems are investigated for selection
combining (SC), equal gain combining (EGC), and maximal ratio combining (MRC)
techniques. Simulations are conducted to compare the numerical results of SC,
EGC, and MRC, and the results show that although the diversity combining
techniques can improve the energy harvesting performance, the power consumption
parameters have a critical importance while determining the suitable technique.
