Matching Network Elimination in Broadband Rectennas for High-Efficiency High Wireless Power Transfer and Energy Harvesting
Abstract: Impedance matching networks for nonlinear devices such as amplifiers and rectifiers are normally very challenging to design, particularly for broadband and multiband devices. A novel design concept for a broadband high high-efficiency rectenna without using matching matching networks is presented in this paper for the first time. An off-center-fed fed dipole antenna with relatively high input impedance over a wide frequency band is proposed. The antenna impedance can be tuned to the desired value and directly provides a complex complex conjugate match to the impedance of a rectifier. The received RF power by the antenna can be delivered to the rectifier efficiently without using impedance matching networks; thus, the proposed rectenna is of a simple structure, low cost, and compact size. s In addition, the rectenna can work well under different operating conditions and using different types of rectifying diodes. A rectenna has been designed and made based on this concept. The measured results show that the rectenna is of high power conversion ersion efficiency (more than 60%) in two wide bands, which are 0.90.9 1.1 and 1.8-2.5 2.5 GHz, for mobile, Wi Wi-Fi, Fi, and ISM bands. Moreover, by using different diodes, the rectenna can maintain its wide bandwidth and high efficiency over a wide range of input power levels (from 0 to 23 dBm) and load values (from 200 to 2000 Ί). It is, therefore, suitable for high-efficiency high wireless power transfer or energy harvesting applications. The proposed rectenna is