Feasibility of a single port flexible antenna array for energy harvesting from ambient sources

In this paper the performance of a single port antenna array is analysed for energy harvesting. Two types of feeds used to feed a flexible patch antenna array are compared. The array consists of 4 rectangular patch antennas made from conductive fabric and Polydimethylsiloxane (PDMS), which are flexible. The proposed array is for energy harvesting for wearable systems. Energy harvesting from ambient energy sources needs an antenna array for collecting a sufficient power level and for wearable applications the array materials must be flexible. For this reason, conductive fabric and PDMS are chosen for conductive and non-conductive parts of the array. However, the array can be fed from a single port signal or individual elements can be fed from simultaneous individual port signals. If the array with a single port has good electromagnetic performance then it is more useful for energy harvesting because it requires single rectifier, which will reduce microwave to DC conversion loss. In this paper these two types of feeding methods are compared with respect to array matching, peak gain and radiation performance. From this comparison we can observe the performance of single port array system for energy harvesting in wearable applications.