ENERGY HARVESTING IN LORAWAN FOR SPACE COMMUNICATIONSTUDENT RESEARCHER: YOLANDA DOLLY NXUMALOSUPERVISOR: DR. BALYAN VIPINCO: DR. GUNJAN GUPTAEXTERNAL SUPERVISOR: DR. PIERRE CILLIERS

INSTITUTION: CAPE PENINSULA UNIVERSITY OF CAPE TOWN

STATEMENT OF RESEARCH

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BACKGROUND_____________________

Industry_____________________

RESEARCH DEVELOPMENTS____________________

In 2019 a tunnel diode was developed at Eindhoven University of Technology, Netherlands which permits an input of 2.4 GHz of −25 to −10 dBm microwave power, the tunnel diode had a higher RF-DC conversion efficiency compared to a conventional SBD. A high RF-DC conversion efficiency can also be obtained using an antenna with a high impedance (Q-matching circuit) as established by the Carnot limit. A low-power and wide-band rectenna with an impedance of >400-Ω was develop at the University of Liverpool and it accomplished a 75% RF-DC conversion efficiency between 0.9-1.1 GHz and 1.8-2.5 GHz. In 2016, Kanazawa Institute of Technology, Japan, designed a 1.6-k high impedance rectenna for the purpose to harvest digital television signals at 500 MHz, that can obtain 49% of RF-DC conversion efficiency given a -15-dBm RF power input, and an 8.7% efficiency can be obtained for an -30-dBm input power

RESEARCH DEVELOPMENTS______________________

At Kyoto University, Japan, Hiroshi Matsumoto steered the research on narrow-beam WPT since the 1980s. In 1992, he prevailed in flying a small airplane with the first narrow-beam WPT with a phased array of 2.411 GHz and fostered some retrodirective WPT frameworks in the 1980s and 1990s. In 1983, he executed the first WPT test with a magnetron from space and in 1993 the second WPT test using a phased array, his point was essentially a SPS (Solar Power Satellite). He additionally improved a SPS demonstrator using a 5.8 GHz at phased array. His innovations are connected to the SPS as well as the business uses of wide-shaft WPT in Kyoto University.

RESEARCH DEVELOPMENTS______________________

In 2015, JAXA worked together with J-Space Systems. They completed an assessment trial to test the accuracy of the advanced phased array for beam forming accuracy by combining target detection and beam forming. One of the techniques uses an amplitude mono pulse with reference point signal, whereas the other uses a rotating electric field vector element technique. The accuracy is adequate considering the 36,000 km transmission distance for a >2-km diameter transmitting antenna requiring a beam forming accuracy of 0.0001 degree. The SPS configuration in Japan for a 36,000-km for a narrow-beam WPT has a beam efficiency of 96.2% with a transmitting antenna of 1.93-km∅ and a receiving antenna of 2.45-km∅ at 5.8-GHz without loss in ionosphere, air, and rain.

PROJECT OBJECTIONS___________________

• TO TRANSFER WIRELESS POWER FOR AT A 10 KM BETWEEN TRANSMITTER AND RECEIVER

• HARVEST ENERGY FOR SPACECOMMUNICATION

• BATTERY-LESS LORAWAN NODE IOT DEVICE

METHODOLOGY__________________

• Solar power satellite with a phased array as the payload for beam forming

• Rectenna as receiver to harvest transmitted energy

• Test three different harmonization techniques to advance efficiency of power management module; ), SDD (space division duplex), TDD (time division duplex) and FDD (frequency division duplex)

• Fly battery-less drone beyond visual line of sight with LoRaWAN node IoT devices attached to test the strength of the signal, the duration of the wireless power transmission and the distance.

DELINEATION OF THE RESEARCH ________________________

The boundaries of this research will be

• Far-field narrow-beam WPT in rural area only

(dense residential areas are not included)

• The maximum distance will be 10 km wireless

power transfer between LoRaWAN gateway

and LoRaWAN nodes

• The phased array will be powered by a Solar

Power Satellite

• The sensors and drone will only be powered by

the target detecting narrow-beam WPT

• The drone will be Class 1A as defined by

SACAA regulations Part 101

SIGNIFICANCE OF THE RESEARCH____________________________

• The development of battery-less devices that are powered by energy harvested from satellite communication will benefit GIS and Remote Sensing Industries by optimising remote sensing operations that use LoRaWAN nodes providing uninterrupted real-time data communication and will significantly reduce operation costs that rely on condition monitoring, anomaly detection and predictive maintenance using remote sensors and drones can fly longer distances advancing operations in remote and hard-to-reach areas. Small drones that are currently manufactured with low-battery capacity can have extended operation hours if they are fed continuous WPT without the need for a battery recharge. The use of solar power satellite (SPS) to power the phased array for target detection narrow-beam WPT (beam forming) will advance solar power satellite (SPS) can receive uninterrupted solar power 24/7, maximize efficiency of energy harvesting.

• Building upon the results of this research it will advance satellite WPT and space communications which will enable real-time data collection and real-time communication from any where on Earth at low cost because LoRaWAN is an open-source communication platform and the devices are battery-free no requirement to recharge.

EXPECTED OUTCOMES, RESULTS, AND CONTRIBUTIONS OF THE RESEARCH

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The expected outcome of this research is an efficient power management module for harvesting energy of far-field target detection narrow-beam wireless power transfer from a phased array for space communication to facilitate real-time communication using LoRaWAN nodes and enable remote operations.