A Device For Energy Harvesting Of Wi Fi Signal Using A Rectenna


Updated about 2 years ago

Abstract

Energy Harvesting and Wireless Power Transmission are the growing research areas to drive wireless mobile devices for unlimited or infinite time. Rectenna is a rectifying antenna which convert RF/Microwave signal into DC signal. In this module a Rectenna device is developed for harvesting Wi-Fi signal at 2.4 GHz. A rectangular microstrip patch antenna array is designned and fabricated in FR 4 substrate at 2.4 GHz frequency. The design of antenna array is optimized using Advanced Design System (ADS) software. HSMS 2862 Schotky Diode is used in the Rectifier for converting received RF signal into DC signal. This DC voltage level is increased by Voltage multiplier. The optimized Voltage multiplier with lumped matching component is then fabricated and fmally a Rectenna is constructed by connecting the patch antenna array with voltage multiplier using a connector. This constructed Rectenna is tested at few cm from the Wi-Fi hotspot. A DC voltage is measured across a load resistor.

Information

Application ID 7121/CHE/2015
Invention Field ELECTRICAL
Date of Application
Publication Number 27/2017

Applicants

Name Address Country Nationality
MR.VINNIYA PERUMAL GANESH ASSISTANT PROFESSOR (SR.GR), DEPARTMENT OF ELECTRONICS AND COMMUNICATION ENGG. SRI RAMAKRISHNA INSTITUTE OF TECHNOLOGY, PACHAPALAYAM, PERUR CHETTIPALAYAM, COIMBATORE - 641 010. India India

Inventors

Name Address Country Nationality
MR.VINNIYA PERUMAL GANESH ASSISTANT PROFESSOR (SR.GR), DEPARTMENT OF ELECTRONICS AND COMMUNICATION ENGG. SRI RAMAKRISHNA INSTITUTE OF TECHNOLOGY, COIMBATORE - 641 010. India India
MR.MANIKANDAN PRAVIN ASSISTANT PROFESSOR, DEPARTMENT OF ELECTRONICS AND COMMUNICATION ENGG. SRI RAMAKRISHNA INSTITUTE OF TECHNOLOGY, COIMBATORE - 641 010. India India

Specification

COMPLETE SPECIFICATIONS

Field of the Invention:

The invention pertains to harvesting of energy from W-Fi signal using a Rectenna device. Rectenna is a rectifying antenna which converts RF/Microwave signal into DC signal.

BACKGROUND OF THE INVENTION
The electrical, electronics and communication companies and government are required the new ideas and technologies in the area of Wireless Power Transmission and Energy Harvesting to drive wireless mobile devices for unlimited or infinite time. The major source for conventional form of electricity transmission is through wire alone. Batteries are needed to be recharged periodically for electronic devices and the charging of batteries relies on Wall plug charger. Charging a battery is more critical in places such as travelling in train or bus, bus stand, railway station and airport. Charging a battery is more serious problem in a disaster condition.
The additional applications of wireless mobile device in the current scenario requires multiple time charging of battery in a day. A huge number of used batteries create pollution environment in the earth for living and non-living objects. The above problems may be overcome by Energy Harvesting or Wireless Power Transmission. Energy Harvesting is a technique to harvest energy from the ambient field. The various ambient sources for harvesting energy are wind, solar, vibration, temperature gracility, heal strike, push button, acoustic and radio frequency wave. Till present the energy generated by this ambient sources are usually less than milliwatt range depending on the technique. This energy harvesting techniques are used in driving ultralow power electronic devices.
WPT is a concept known as transmitting power from one point to another point without wires using either near or far field methods. Inductive coil is used in the near field method and other side Rectenna is used in the far field method. The far field WPT technique may use in the applications such as Solar Power Satellite to generate electricity, charging a Robot for industry automation and charging a device under disaster condition. The Rectenna is also used in the Radio Frequency Energy Harvesting which is a combination of an antenna and a rectifier. The antenna is used to receive the RF/Microwave signal from ambient or self-generated source. The rectifier is used to convert the received RF/Microwave signal into DC signal. The RF energies present in ambient are AM, FM, TV, mobile Phone and Wi-Fi signals.
Jerry Petterson (Indian Patent No: 226042) claimed the system for interior cooling of container using a Rectenna wherein the rectenna comprises at least one microwave antenna such as dipole, patch or loop antenna array, a low pass filter, a rectifying diode, a DC filter and a load resistor. This proposed work is related to Wi-Fi signal energy harvesting. Silver Guy and WU Juinerong (Indian Patent Application No: 3161/DELNP/2007) claimed the model for electrical power generation using Rectenna in conjunction with a natural breakdown device wherein a rectenna element generates current from two sources based upon the power of the incident EM wave and from an n-type semiconductor or another electron source attached to a maximum voltage point of an antenna element. In this work the energy is harvested using rectenna alone.
Lockheed Martin Corporation (Indian Patent Application No: 910/DEL/2008) claimed a dual system that integrates a power transmission/reception function and a RADAR imaging function with an airship or other lighter than air platform. In their claim a patch array carried by an airship is configured to receive an energy beam from a phase array antenna maintained by the ground station. The antenna in this rectenna also used to transmit and receive signal for image processing applications. This work is related to low power energy harvesting.

SUMMARY OF THE INVENTION

In this work a Rectenna model is developed for harvesting Wi-Fi signal at 2.4 GHz. Rectenna is a rectifying antenna. A rectangular microstrip patch antenna array is designed and fabricated in FR 4 substrate at 2.4 GHz frequency. The antenna array design is optimized using Advanced Design System (ADS) software. From the simulation results, antenna parameters such as return loss, directivity, gain, effective angle and radiation pattern are obtained. The designed antenna is then fabricated and the return loss is also measured using a Network Analyzer. HSMS 2862 Schotky Diode is used in the Rectifier for converting received antenna RF signal into DC signal. This DC voltage level is increased by multiplier circuit. A Voltage multiplier is designed and their passive components are optimized using the ADS software. This optimized Voltage multiplier with lumped matching components is then fabricated. Finally a Rectenna is constructed by connecting the patch antenna array with voltage multiplier using a connector. This constructed Rectenna is tested at few cm from the Wi-Fi hotspot. A DC voltage is measured across a load resistor.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWING
The block diagram of the proposed work is shown in Fig.l. The block diagram consists of source, receiving antenna, matching circuit, rectifier and load. Receiving antenna, matching circuit and rectifier are combined together act as a Rectenna. Air medium is present in between source and rectenna. A Wi-Fi hotspot (1) is used as the source for this work which transmits the signal at 2.4 GHz frequency. Antenna in the Rectenna is used to receive the radiated Wi-Fi signal from the Wi-Fi hot spot. An important issue in the rectenna design is antenna (2) because the designed antenna should have the properties such as high gain, small in size, polarization match, and impedance match. The efficiency of the rectenna increases when the gain of the antenna increases. As the gain of the antenna increases dimensions of the antenna also increase so there is a trade of between gain and size. The antenna operates in various directions of the incident field for higher half power beamwidth. There is inverse relation between gain and half power beamwidth of the antenna so there is one more trade of between gain and half power beamwidth.
In this work a rectangular microstrip patch antenna array is designed with insert feed technique using ADS software and fabricated in FR 4 substrate. The dielectric constant of 4.2, loss tangent of 0.001 and thickness of 1.6 mm are the specification of the designed antenna substrate. Initially a single rectangular microstrip patch antenna is designed at 2.4 GHz frequency and the antenna parameters are optimized.
A micorstrip power divider/coupler network is designed using ADS software and its scattering parameters are obtained. This coupler is constructed using quarter wave line and 50Q line. A two element rectangular microstrip patch antenna array is constructed by connecting the power divider line to the two antenna element. The gerber file of the designed antenna is generated from the software for fabrication. The return loss of the antenna from the simulation and testing results are obtained.
The return loss of the fabricated antenna array is tested using an Agilent N5230A Network Analyzer. From the simulation results, radiated power, effective angle, directivity, gain and maximum intensity of the array are obtained. The received signal from the antenna is passed to the rectifier (4) through matching circuit. A Voltage multiplier is used as a rectifier and boosts the voltage level This multiplier circuit is designed and the capacitance values are optimized using ADS software at 2.4 GHz frequency. From the simulation result, DC output voltage is obtained for the self-generated input power. HSMS 2862 Schottky diode is used in the multiplier circuit for rectification. The impedance of the rectifier section and antenna are matched (3) using lumped component and their values are optimized using Smith Chart utility in ADS software. The power conversion efficiency of the rectifier is determined by series resistance, zero-bias junction capacitance and breakdown voltage.
The series resistance affects the efficiency. The zero-bias junction capacitance values define how harmonic currents affect the diode. A high speed switching characteristic of diode is necessary for high frequency signal. Low cut-off voltage is another requirement of the diode for energy harvesting circuit. In this work, the selected HSMS diode has low value of series resistance of 5Q., low value of junction capacitance of 0.18 pF and breakdown voltage of 7 Volt. Finally a Rectenna is constructed by connecting the patch antenna array with voltage multiplier using a connector. This constructed Rectenna is tested at few cm from the Wi-Fi hotspot. A DC voltage is measured across the load resistor(5).

We Claim

1. A set-up for harvesting energy from Wi-Fi signal using a Rectenna at 2.4 GHz.
2. Energy harvesting from Wi-Fi signal using a Rectenna at 2.4 GHz as claim 1 wherein the assembly of rectangular microstrip patch antenna array for receiving the Wi-Fi signal, HSMS 2862 Schotky diode for rectification and voltage multiplier for boost the voltage level.

3. Energy harvesting from Wi-Fi signal using a Rectenna at 2.4 GHz as claim 1 wherein the harvesting the energy from Wi-Fi signal at 2.4 GHz.

Documents

Name Date
7121-CHE-2015-Other Patent Document-311215.pdf 2016-02-11
7121-CHE-2015-Form 2(Title Page)-311215.pdf 2016-02-11
7121-CHE-2015-Form 1-311215.pdf 2016-02-11

Orders

Applicant Section Controller Decision Date URL