A broadband integrated rectenna for microwave radio energy harvesting using an integrated hybrid sandwich power divider

Abstract

Traditionally, rectennas have been designed and implemented for single or narrow frequency ranges. However, to utilize these systems in promising applications such as the Internet of Things (IoT), wireless sensor networks, and to enhance power reception in telecommunications devices, it is necessary to design and develop rectifying antennas that operate across a broader frequency range. This paper presents a broadband rectenna system designed to harvest ambient radio frequency energy using a sandwich-type hybrid power combiner (HPC) for operation in the 2–18 GHz frequency range. The proposed integrated system incorporates a Vivaldi receiving antenna with a return loss of -13 dB across the entire frequency range and a three-layer sandwich-type power divider circuit design. The power divider features a coupling factor within the 3-dB range and a phase factor with an error margin of less than ±3°. The broadband power divider section is implemented without using lossy elements such as resistors and capacitors, employing only integrated tandem line techniques and simultaneous stripline coupling with an 8.34 dB coupling factor and equal 3 dB outputs on a Ro 4003c substrate. The proposed rectenna in this design achieves a power conversion efficiency of 72 % in simulation mode. This system maintains an efficiency of over 50 % across a load resistance range of 900 to 3000 ohms at an input power of 0 dBm. The sandwich rectenna operates with an efficiency of over 28 % in the frequency range of 2 to 18 GHz, with input power ranging from -15 to +15 dBm. The system functions effectively even at very low radiation power densities, such as 305 microwatts, achieving an efficiency of more than 40 %. results indicate that the proposed broadband rectenna serves as a power supply for modern devices in Internet of Things (IoT) applications.