Multi-Band Microstrip Antenna Design for Wireless Energy Harvesting

The purpose of this work is to propose an efficient microstrip rectenna operating on 900/1800 MHz GSM bands and the 2.4 GHz ISM band. The receiving antenna with presented joint feeding line implemented in a multilayer substrate. The reflection coefficient at the input of the optimized multi-Band microstrip patch antenna is below -10dB over the every frequency band. The measurement results are in excellent contract with the CST STUDIO SUITE 2011 simulation results

Design Of Circularly Polarized Rectenna With Harmonic Rejection Capabiltity At 2.45 Ghz For Microwave Energy Transfer

Nowadays, with the fast development in wireless devices, microwave energy transfer in which energy is transmitted from one point to another without wires, becomes more vital. There are many applications in which microwave energy transfer technology can be utilized such as smart healthcare, environmental monitoring, and home automation. Microwave energy transfer has the advantages of easy communication and lower cost compared to traditional transmission mediums. A rectifying antenna or rectenna which consists of receiving antenna, rectifier, matching network, and output DC filter, is an important element in microwave energy transfer. The antenna receives RF signals that are converted from alternative current (AC) into usable direct current (DC) by the rectifying circuit. Rectifying diodes have nonlinear behavior which generates harmonics and degrades RF-to-DC conversion efficiency of the rectenna. Harmonic rejection filter is used to suppress these harmonics. However, adding harmonic rejection filter increases the size and cost of the rectenna. Antennas with harmonic rejection is used to replace the harmonic rejection filter. However, the proposed antennas have a low gain which degrades rectenna conversion efficiency. To increase the amount of collected RF signals, circular polarization, dual-band and broadband operation are adopted but these techniques increase the size and design complexity. This thesis proposed a rectenna design with harmonics rejection and circular polarization at 2.45 GHz to enhance the RF-DC conversion efficiency. The harmonic rejection capability is achieved using triangular aperture coupling slot. The circular polarization property is achieved with a single feed line which reduces the size and design complexity. The aperture coupled antenna is simulated with an air gap to enhance the gain, using Computer Simulation Technology (CST). The voltage doubler rectifier is simulated with a fast switching HSMS286B Schottky diode, using Advance Design System (ADS). The fabrication process is carried out using a low-cost 4.4 permittivity FR-4 substrate. The antenna can reject harmonics up to 10 GHz with -50 dB return loss, 7 dB gain, 1.5 dB axial ratio and 40.8% axial ratio bandwidth. The doubler rectifier with radial stub filter can provide output DC voltage higher than 7 V. The measured RF-to-DC conversion efficiency of the integrated rectenna is 76.84%. at an input power of 20 dBm. The proposed rectenna has the advantages of harmonic rejection, circular polarization, high gain and low cost which make it a suitable candidate for microwave energy transfer

Enhanced Antenna Design for Rectenna Application in the 2.45 GHz ISM Band

In this paper a two layers microstrip antenna design at 2.45 GHz ISM band with Harmonic rejection filter embedded on the ground plane is presented. The two roger substrates with relative permittivity of 2.2 are separated by an air gap which enhances the antenna gain. The design is simulated using Computer Simulation Technology (CST) Studio Suite 2015. Different aperture couplings slots such as rectangular and triangular aperture coupling slots are studied and compared. It is found that the antenna with triangular aperture coupling slot enhances the antenna performance by suppressing 2nd and 3rd harmonics at 5 GHz and 8 GHz, respectively, increasing the antenna gain and providing a better circular polarization behavior. The simulated antenna design achieves a gain of 9 dB, return loss of -23.6dB, axial ratio of 1.27dB and axial-ratio bandwidth of 40.8% (2 ~ 3 GHz). The proposed antenna shows an enhancement in the antenna performance which makes it a suitable candidate for rectifying antenna or rectenna application as it can increase the total conversion efficiency resulting in a high output DC voltage used to power low power electronic and electrical devices such as wireless sensor

Compact circularly polarized truncated square ring slot antenna with suppressed higher resonances

This paper presents a compact circularly polarized (CP) antenna with an integrated higher order harmonic rejection filter. The proposed design operates within the ISM band of 2.32 GHz± 2.63 GHz and is suitable for example for wireless power transfer applications. Asymmetrical truncated edges on a square ring create a defected ground structure to excite the CP property, simultaneously realizing compactness. It offers a 50.5% reduced patch area compared to a conventional design. Novel stubs and slot shapes are integrated in the transmission line to reduce higher (up to the third) order harmonics. The proposed prototype yields a -10 dB reflection coefficient (S11) impedance bandwidth of 12.53%, a 3 dB axial ratio bandwidth of 3.27%, and a gain of 5.64 dBi. Measurements also show good agreement with simulations. © 2017 Sabran et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

MODIFIED EDGE FED SIERPINSKI CARPET MINIATURIZED MICROSTRIP PATCH ANTENNA

This paper presented a modified edge fed Sierpinski carpet microstrip patch antenna for antenna miniaturization. The proposed design was etched as Sierpinski carpet to lower the antenna resonant frequency, which is used to reduce the conventional patch antenna size. After the Sierpinski carpet second iteration, the proposed antenna was modified by replacing the rectangular slot in the middle of the patch with a circular slot. Simulation results showed that the proposed antenna achieved 46.5% size reduction when compared with the main patch antenna without affecting the resonant frequency and radiation patterns. http://dx.doi.org/10.4314/njt.v35i3.2

Broadband PIFA Rectenna Design for a Multi-Source Energy Harvesting Device

Combining different energy harvesting devices to optimize output power is crucial to the achievement of sustainable energy. This thesis focuses on the design, simulation and fabrication of a broadband Planar Inverted-F Antenna (PIFA) constructed for energy harvesting and its integration with a solar cell. An assessment of available ambient RF energy was performed by surveying power density levels from 700MHz to 18GHz. The measured spectrum was then used to determine the bandwidth for our rectifying antenna. The PIFA design was chosen for its small size and low profile, in order to limit the area covering the solar panel. The purpose of this antenna is to harvest power during the times that solar energy is unavailable. The thorough analysis, design and fabrication specifics of the antenna and its integration with the solar panel are discussed in detail. Future work involving the implementation of a PIFA array to optimize the amount of energy harvested is also presented

Circular Polarized Antenna for Radio Frequency Energy Harvesting Applications in the Smart Cities

Objectives: In this work, the Circularly Polarized (CP) broadband antenna with a simple monopole structure is proposed. Method: The antenna includes the rectangular patch antenna slotted with the four arcs in a circular shape and Top-right, and down-left vertices are removed to obtain the CP and to harvest power from the frequency 1.95-3.05 GHz, it covers the LTE 2100 GHz and Wi-Fi 2.45 GHz, bands. The defected ground structure is considered to design the broadband frequency. The antenna is excited using microstrip feeding. The proposed antenna is simulated, fabricated, and measured. The Dimensions of the antenna are 45 mm x 50 mm x 1.6 mm. Findings: The maximum gain obtained was 4.71dB at a frequency of 2.45 GHz with a Return loss of -43.21 dB, the axial ratio (AR) obtained 1.98dB (less than 3dB) in the same frequency. The impedance bandwidth of 59.8% and 44.89% simulated and measured, respectively, at 2.45 GHz, and VSWR is 0.128 and 1.142 at 2.45 GHz for the simulated and measured, respectively. Novelty: The designed antenna radiation Phenomenon resembles omnidirectional characteristics. Rectenna is designed at 2.45GHz and is connected to the antenna with the help of an impedance matching network. It is used to achieve the RF- DC power conversion efficiency of 84.52%