Co-design of dual-band GSM filtenna based on printed-IFA for energy harvesting

Interest in radiofrequency energy harvesting (EH) systems for green and renewable energy schemes has increased remarkably in recent years thanks to their unlimited applications. The key element on the receiving side of an EH system is the rectenna (rectifier + antenna) which receives electromagnetic power and converts it into electric power. In order to reduce the size of the rectenna, it has been suggested to combine antenna and filter together. This kind of antenna is sometimes called “filtenna”. We present in this paper a dual-band filtenna for application of harvesting RF energy from cellular network frequency bands (900 MHz and 1800 MHz). By using the principle of Printed-Invert-F-Antennas and a slot on the ground plane of the antenna, the high-order harmonics are rejected. Thus, the antenna acts as a dual-band-pass filter for the 900 MHz and 1800 MHz bands and as a stop-band filter for the higher frequencies. The measured antenna return loss over the frequency band from 2 GHz to 8 GHz is less than 1.5 dB so all the high-order harmonics are suppressed. The realized gains of the antenna are 1.9 dBi and 2.55 dBi at 900 MHz and 1800 MHz, respectively.