Circularly polarized multiband microstrip antenna with rf energy harvesting for low power sensors applications

Abstract

Nowadays, wireless sensors are widely deployed in communications for designing smart devices. They have need of a continuous power supply for their operation which requires replacement of batteries from time to time. To provide constant power replenishment of wireless sensor devices, various methods are being explored to harvest it efficiently which from freely available sources of energy like solar, thermal, wind, and RF (Radio Frequency). RF energy harvesting is the possible solution to harvest free and wasted energy from the environment for different wireless applications according to the requirements of wireless devices. There is a need to develop and design an antenna that can efficiently harvest the freely available RF energy from the wireless towers. A microstrip antenna is widely used in the field of wireless communication because it provides high gain, large bandwidth, good impedance, polarization, and resonant frequency. A circularly polarized multiband antenna can be used for harvesting the available RF energy from the environment. newlineFurthermore, rectifier circuit is most important to convert the RF power harnessed by the antenna to usable DC (Direct Current) output power. With the use of a wideband energy harvester, a high output voltage has been promised in order to collect more RF signals from various frequency bands. However, the limitations could include the decreased conversion efficiency caused by frequency- dependent change, which makes it challenging to maintain the impedance match across a broad frequency range. newline