Efficient compact dual-band antennas for GSM and Wi-Fi energy harvesting

Since the demand for autonomous wireless sensors increases, there is an important interest in battery-less systems that use radiofrequency (RF) energy harvesters. The key element on the receiving side of an energy harvesting system is the rectenna (rectifier + antenna) which receives electromagnetic power and converts it into electric continuous power. With the development of multiple frequency bands in today´s wireless communication systems, the multi-band rectennas would be useful. Among various entities of rectenna, antenna is one of the important elements which is responsible for collecting the incoming RF signals of various frequencies. We present in this paper two efficient compact dual-band antennas for RF energy harvesters: a Printed-IFA for GSM bands with 1.3 dBi at 900 MHz band and 3.2 dBi at 1800 MHz band; and a quasi-Yagi for Wi-Fi bands with 5.7 dBi at 2.45 GHz band and 5.9 dBi at 5.3 GHz band. Also simulation and measurement results will be presented.