High-efficiency Rectenna Research Articles

Wideband Circularly-Polarized High-Efficiency Rectenna with Large-Angle Wireless Power Capture Capability

Wideband Circularly-Polarized High-Efficiency Rectenna with Large-Angle Wireless Power Capture Capability

Compact high-efficiency broadband/multi-band stacked back-to-back high-gain rectenna based on fourth-order bandpass filter for green environment applications

This paper presents a high-efficiency rectenna based on a high-gain wideband antenna and a wideband rectifier circuit with a fourth-order bandpass impedance matching transformer. The peak measured power conversion efficiency (PCE) of the rectifier hits 73.57% at an input power level of 10 dBm and at a center frequency of 5.4 GHz. The maximum measured DC output voltage is 4.82 V and 4.7 V at 5.2 GHz and 5.8 GHz, respectively. The proposed rectifier exhibits broadband high-efficiency rectification performance concerning PCE and output voltage as its PCE is higher than 50% within a range from 4.9 to 6.1 GHz at a wide range of input power levels from −4 to 10 dBm. The stacked back-to-back profile saves 50% of the total area of the rectenna. The rectenna operates through a wide bandwidth of 1.3 GHz. It is capable of harvesting power at six interesting bands 4.9 GHz (5G), 5 GHz (WLAN), 5.2 GHz (Wi-Fi), 5.5 GHz (WLAN), 5.8 GHz (ISM), and 6 GHz (Wi-Fi 6E). The maximum measured PCE and DC voltage of the rectenna are 71.46% and 1.87 V, respectively at 10 dBm, 2 KΩ load termination, and 50 cm transmitter-rectenna spacing.

Compact and High-Efficiency Rectenna for Wireless Power-Harvesting Applications

A compact, single-layer microstrip rectenna for dedicated far-field RF wireless power-harvesting applications is presented. The proposed rectenna circuit configurations including multiband triple L-Arms patch antenna with diamond slot ground are designed to resonate at 10, 13, 17, and 26 GHz with 10 dB impedance bandwidths of 0.67, 0.8, 2.45, and 4.3 GHz, respectively. Two rectifier designs have been fabricated and compared, a half wave rectifier with a shunted Schottky diode and a voltage doubler rectifier. The measured and simulated maximum conversion efficiencies of the rectifier using the shunted diode half-wave rectifier are 41%, and 34%, respectively, for 300 Ω load resistance, whereas they amount to 50% and 43%, respectively, for voltage doubler rectifier with 650 Ω load resistance. Compared to the shunted rectifier circuit, it is significant to note that the voltage doubler rectifier circuit has higher efficiency. Both rectifier’s circuits presented are tuned for a center frequency of 10 GHz and implemented using 0.81 mm thick Rogers (RO4003c) substrate. The overall size of the antenna is 16.5 × 16.5 mm2, and the shunted rectifier is only 13.3 × 8.2 mm2 and 19.7 × 7.4 mm2 for the voltage doubler rectifier. The antenna is designed and simulated using the CST Microwave Studio Suite (Computer Simulation Technology), while the complete rectenna is simulated using Agilent’s ADS tool with good agreement for both simulation and measurements.

Design of high-performance dual-polarized rectenna for microwave wireless power transmission

This paper presents a 5.8 GHz high-efficiency dual-polarized rectenna for microwave wireless power transmission. The rectenna consists of a 5.8 GHz dual-polarized receiving antenna and a 5.8 GHz class-F rectifier. A metallic probe is used to integrate the receiving antenna and the rectifier. The receiving antenna is a 2×2 microstrip array antenna and the metal ring loading technology is adopted to improve the rectenna’s impedance bandwidth and robustness. The metal probe instead of the conventional microwave connector and cable is utilized to realize the integration of receiving antenna and rectifier circuit, thus simplifying the structure and reducing the weight, loss and cost of the rectifier antenna. A prototype of the dual-polarized rectenna is fabricated and its rectifying efficiency is measured and compared with the linear-polarized rectenna with the same aperture area. The measured results show that the maximum conversion efficiency of the dual-polarized rectifying antenna reaches 76.8% under the optimum incident power density of 1.47 mW·cm−2. Compared to the linear-polarized rectenna, when the polarization direction of the incident wave varies from 0° to 90°, the conversion efficiency of the rectenna antenna is always above 62% with stable DC output and the rectenna antenna exhibits excellent all-polarization receiving rectification performance.

Design and Development of High Efficiency Rectenna for RF Harvesting

In this paper, we propose a compact and highly efficient Rectenna design (rectifying antenna), operating on ISM band with the center frequency of 2.4 GHz. A RF to DC conversion through Schottky diode (HSMS2860) is used to generate the dc voltage to operate a battery-less Sensor for RF power harvesting using the designed Rectenna. We have achieved more than 80% efficiency through Advanced Design System (ADS-2016) simulation software at different power densities. Further a rectenna circuit is designed using RF to DC Schottky detector diode and a microstrip patch antenna. The rectenna circuit design is simulated through ADS 2016 simulation software. The Battery less sensor requires 1.8V- 2.5V dc voltage to perform an optimum performance. As per simulation and theoretical/practical modeling we have achieved more than 80% efficiency at single Schottky diode and its operating from 915 MHz to 5.8 GHz. Rectenna operates at lower power densities start from 0.4uW/cm. The proposed rectenna design is a possible candidate to be used for mobile/sensor application without Battery

A wide-beam, circularly polarized, three-staged, stepped-impedance, spiral antenna for direct matching to rectifier circuits.

This paper presents a novel antenna element with varying complex input impedances from 203 to 303 Ω for the real part and 360 to 127 Ω for the imaginary part and a wide circular polarized (CP) beam that could be used for high efficiency rectenna applications. The efficiency of the antenna is about 88%. Tuning the real and imaginary parts of the antenna impedances to the desired values directly matches the complex conjugate to the rectifier impedance. The antenna element is designed with an artificial magnetic conductor at the back of a spiral antenna operating at a center frequency of 2.5 GHz with a CP beam width of 179° and a bandwidth of 400 MHz. This prototype antenna overcomes the low polarization losses and the need for a matching network, which is useful for high efficiency rectenna applications.

Maximum Achievable Power Conversion Efficiency Obtained Through an Optimized Rectenna Structure for RF Energy Harvesting

High-efficiency rectennas for radio frequency (RF) energy harvesting have been studied for decades, but most of the literature straightforwardly applies the rectenna aiming at dedicated RF sources to this situation, even though the level of input power is significantly different. Since previous studies address antenna design collecting more ambient RF power, the improvement of power conversion efficiency (PCE) has emerged in a scattered way, because the theoretical limit of PCE has not yet been characterized, and the optimal rectenna structure approaching such maximum PCE is still uninvestigated. In this paper, we characterize the performance limit of rectennas with input power ranging from −20 to 0 dBm, proposing optimal rectenna design demonstrating the maximum PCE. The maximum achievable PCE is cast into a mathematical programming problem. Solving this optimization model clarifies the effect of design factors, including operational frequencies, rectifier topologies, and parameterization. To achieve the maximum PCE, our investigation shows that the optimal rectenna structure should not only optimize those design factors but also eliminate the matching circuit between an antenna and a rectifier for ultralow-power scenarios. The resultant PCE at 2.45 GHz is 61.4% and 31.8% at −5 and −15 dBm, respectively, closely approaching the theoretical bound.

Matching Network Elimination in Broadband Rectennas for High-Efficiency Wireless Power Transfer and Energy Harvesting

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-efficiency rectenna without using matching networks is presented in this paper for the first time. An off-center-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 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. 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 efficiency (more than 60%) in two wide bands, which are 0.9–1.1 and 1.8–2.5 GHz, for mobile, Wi-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 Ω). It is, therefore, suitable for high-efficiency wireless power transfer or energy harvesting applications. The proposed rectenna is general and simple in structure without the need for a matching network hence is of great significance for many applications.

Development of one-dimensional photonic selective emitters for energy harvesting applications

The small wavelength utilizable range used for determining the optimum performance of photovoltaic and rectenna devices, compared to the broad band spectrum of solar or other heat sources, limits the energy conversion efficiency of such technologies. A selective emitter, with an emissivity profile that matches the receiver's characteristic bandwidth, can be used to improve the overall efficiency of such energy harvesting devices. This paper compares simulated and experimental results of the design and fabrication of a selective emitter that can be used in the 8–12µm frequency range. The matrix transform method is used to calculate the radiative properties of one dimensional metal-dielectric photonic structures. By using genetic algorithm as a powerful optimization tool, the simulated design characteristics of such structure are adjusted to minimize the mean square deviation of the actual spectral emissivity from the target emissivity profile. Specifically, this paper presents and compares results of the simulated design and fabrication of selective emitters composed of alternating layers of Al2O3-SiO2 or Al2O3-SiC on an aluminum substrate. The output radiation of these selective emitters could be used as the input radiation to high efficiency rectenna devices.

A C-band microwave rectenna using aperture-coupled antenna array and novel Class-F rectifier with cavity

A rectenna (rectifying antenna) is usually applied to a microwave power transmission (MPT) system as a terminal, which receives microwave (MW) power and converts them into DC power. A 5.8 GHz aperture-coupled patch antenna array is developed with a gain of 19.5 dBi, which is a part of the rectenna. A novel Class-F rectifier with a series diode is proposed to achieve a high rectifying efficiency based on harmonic termination techniques. The input circuit of the proposed rectifier is taken into consideration to reach the Class-F condition, while mostly only the output circuit is involved in conventional Class-F designs. A low-pass filter based on defected ground structure is implemented, which not only blocks the harmonics produced in rectifying but also presents desired impedance at harmonics. The current and voltage waveforms on the diode are well enforced. The radiation feature of the rectifier is presented as well. It shows that an optimized cavity, which shields the parasite radiation, may achieve a 5% enhancement on the MW-to-DC conversion efficiency. A C-band rectifier based on HSMS-286 Schottky diode is fabricated and measured. A MPT simple demo system is constructed with the proposed rectifier and antenna. A measured maximum MW-to-DC conversion efficiency of 72% is achieved on the rectifier. The design method is extremely valuable in a high conversion efficiency rectenna design based on harmonic termination techniques.

All Polarization Receiving Rectenna With Harmonic Rejection Property for Wireless Power Transmission

In this paper, a high conversion efficiency rectenna for wireless power transmission at 2.45 GHz is proposed. The rectenna is fabricated on a low-cost FR-4 substrate. The proposed design contains a dual circularly polarized patch antenna in which a high-order harmonic rejection property is embedded, and a pair of rectifying circuits without harmonic rejection filters. The dimension for the proposed rectenna design is 100×100×3.8 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> . The proposed rectenna collects waves in all polarization senses simultaneously with a suitable air gap width, chosen to maximize antenna gain, and provide high isolation between the rectifying circuits. The rectifying circuits are fed by the wave power of orthogonally polarized waves. The conversion efficiency is improved by blocking the second and the third harmonic noise from reemission without suffering loss from filters: the second harmonic noise is rejected with a T-shape slot, while the third is rejected by a U-shape resonator. The measured conversion efficiency of the proposed rectenna reaches 82.3% when the inputs of the rectifying circuits are fed at 22 dBm, surpassing the majority of existing rectenna designs in the current literature. The functionality of reception at all polarizations is also verified, distinguishing our design from other proposals.

2.4-GHz High-Efficiency Rectenna Using an In-Phase Partially Reflective Surface and High-Order Harmonic Reject Bandpass Filter

A high-efficiency rectenna is designed at 2.4 GHz. In general, a rectenna consists of an antenna, a band-pass filter, a rectifying diode, and a low-pass filter. In this article, to increase transmission efficiency, a high-directional antenna is developed using partially reflective surfaces. In addition, the harmonic rejecting band-pass filter is designed to suppress the second and third harmonic signal from the nonlinear diode, resulting in high conversion efficiency. It is experimentally demonstrated that the proposed rectenna achieves an RF to DC conversion efficiency of 72.17% when the received RF power is 63.09 mW at 2.4 GHz.

Performance Analysis of Rectenna Using Closed Form Equation

Electromagnetics has an important role in power and energy industry. In this paper, the concept of rectenna is introduced firstly. The times past of rectenna for wireless energy harvesting and transmission is then reviewed. Finally examples are employed to illustrate some rectenna design and measurement issues such as rectenna impedance matching and its conversion efficiency. It isalso shown that rectennas can harvest wireless energy efficiently under certain conditions and have the potential to become a power supplier for some special applications. A high-efficiency rectenna component has been calculated and experienced at 6.2 GHz planned for applications involving microwavepower show. The dipole mast and filtering circuitry are printed on a thin duroid substrate. A silicon Schottky barrier mixer diode with a low fail voltage is used as the rectifying device. The rectenna component is tested inside a waveguide simulator and achieves an RF-to-dc conversion efficiency of 85% at an input power level of 55-mW and 347-load. Closed-form equations be agreed meant for the diode efficiency and effort impedance as a sense of payment RF power. Measured in addition to intended efficiency results are in first-class agreement. The mast and circuit design are base on a full-wave electromagnetic simulator. Next harmonic power levels are 19 dB down from the primary input power.

Dependence of dc output of a rectenna array on the method of interconnection of its array elements

In 1994 and 1995, a ground-to-ground microwave power transmission (MPT) experiment was carried out by a group including participants from Kyoto University, Kobe University, and Kansai Electric Power Company. Among the MPT technologies, which are one of the most important key issues for the realization of the Solar Power Satellite, the “rectenna” (rectifying antenna) has been studied to achieve higher efficiency of conversion from microwave to dc We had developed a new rectenna panel which can effectively rectify a microwave power of 2.5 W at 2.45 GHz, prior to the ground-to-ground MPT field experiment. We examine the sum of the outputs of two or three rectenna panels which are connected either in parallel or in series or in a hybrid manner under the same microwave circumstances. The experiments lead us to conclude: (1) The sum of the dc outputs from two rectenna panels connected in parallel is larger than that from those connected in series. (2) The sum of the dc outputs of two rectenna panels is generally smaller than the sum of the dc output of the individual panels unless their outputs are equal. (3) Better total output dc power of a rectenna array is achieved when we take careful account of the array element balance. Based on the experiments, we propose an optimum method for connection of individual rectenna elements to form a high-efficiency rectenna array. © 1998 Scripta Technica, Electr Eng Jpn, 125(1): 9–17, 1998

Design and experiments of a high-conversion-efficiency 5.8-GHz rectenna

A high-efficiency rectenna element has been designed and tested at 5.8 GHz for applications involving microwave-power transmission. The dipole antenna and filtering circuitry are printed on a thin duroid substrate. A silicon Schottky-barrier mixer diode with a low breakdown voltage is used as the rectifying device. The rectenna element is tested inside a waveguide simulator and achieves an RF-to-DC conversion efficiency of 82% at an input power level of 50 mW and 327 /spl Omega/ load. Closed-form equations are given for the diode efficiency and input impedance as a function of input RF power. Measured and calculated efficiency results are in good agreement. The antenna and circuit design are based on a full-wave electromagnetic simulator. Second harmonic power levels are 21 dB down from the fundamental input power.