Motivation:The ever increasing demand forthe energy has led to the search for the alternative sources for it.

Onesolution to this is the exploration of ambient sources of energy. There arenumerous available sources of energy in the environment that can be harnessed;the sources are in the form of vibration, solar, and Electromagnetic (EM) wavesor RF signals. Vibration and Solar sources may not be available all the time,for example in a cloudy season we cannot get solar energy. On the other handthe EM wave is always available. Over the past few years there has been tremendousgrowth in the Internet of things (IoT) domain which encompass the mobile basestation, TV broadcast station, Wi-Fi etc which are also the sources of EM waves.However, extracting energy from these micro sources are very challenging as theenergy contents are very less in amount.

One major motivation towards this isthat such sources are available in billions and that only keeps on growing.Therefore, if such sources are utilized it would be a true solution to theenergy need of the mankind.                Attributingto the unprecedented development in the mobile communication, recently,research in the energy harvesting from the RF signal has picked up the pace 4-15.Therefore, energy harvesting from the ambient RF sources is seen as the potentialresearch domain for the energy need exploration 1.Fig. 1. Block diagram of RF energy harvestingsystem  *(PMM: Power management module)Fig. 1 shows the general schemefor the Energy harvesting system.

The antenna picks up the signal from theambient and fed to the non-linear block which is generally comprised of the Schottkydiode to convert this into the dc. It is then followed by a filter thateliminate the ripple contents 2, 4. Finally, it is stored or utilized topower the low power IoT devices. Antenna is followed by an impedance matchingnetwork, this block is very important with respect to the maximum powertransfer 5-6. Its purpose is to match the impedance of antenna to thecomplex impedance of the rectifier over a broader band of frequency range therebymaximizing the power content and signals dynamic range.

The storage element andthe power management module (PMM) present an optimum load for achieving highefficiency. Recently, the power amplifier (PA) based configuration has gainedincreased interest 8-9 as the rectifiers are comparatively less efficient 7,13. The whole process of this extraction of RF to DC is very challenging ascribingthis to the very low level of available RF signal, it therefore necessitates toachieve high efficiency in such system.

Not least, the location dependency and randomnessof the sources exacerbate the task 1. In this context, many research havebeen reported which are based on the optimization process than on theanalytical methods. Till now, the reported schemes have only achieved anefficiency in the range of 15-20 % with a maximum available power of -15 dBm,which is way below to be utilized in the real system. Energy harvesting concurrentlyfrom two frequency sources have also been reported 2, 14 but it is limited onlyto the lower frequencies as the lumped elements constrain its use at higherfrequencies.

Impedance compression technique is also limited to higher ambientpower source regions 4. The PA based system is still in the development as itrequires higher power level than available 8-9. Therefore, in order to successfullyharness energy it is imperative that efficient RF energy harvesting schemes bedevised.        In order to successfully implement the aforementioned research goal,there are various steps to be taken by the applicant. It involves course study,literature survey, proposing design scheme, simulation, prototype preparation,test and measurements. Apart from this, collaboration with faculty members basedwithin the university and at other universities may also be required. Finally, itwill finish with publications and reporting etc.

The above mentioned steps can bebreak into two levels, Master and PhD.Masterlevel Research:It mainly involves the courses study to make a stronger foundation.Below are the subjects that need to be studied for it.1.     Electromagnetics2.

     Antenna design3.     Embedded system4.     Analog CMOS circuits5.

     RF circuit design6.     Digital Signal Processing7.     Electronic Devices8.     Digital VLSIIn parallel, literature survey and research thesis based on theplanned research is to be followed. Some research are to be published. Finally,a thesis report based on the research is to be prepared. PhD levelResearch:After having strong theoretical knowledge at Master level with researchbackground, a full fledge research for the implementation of the plannedresearch is to be carried out.

It involves the below listed steps. 1.     Diode-based highly efficient rectifier design, prototyping and measurements.2.     Highly efficient PA rectifier design in collaboration with otherdepartments, fabrication and measurements.3.

     Effective Antenna design, fabrication and measurement4.     Powermanagement module design in collaboration with other departmental faculties. Finalsystem integration, measurements.5.

     Paper writing (IEEE Journals: TMTT, MWCL, TCPMT, TCAS-1 & 2)and presentation at top Conferences (IEEE IMS, WPTC, EUMC, MWSCAS) References:1S.Hemour and K. Wu, “Radio-frequency rectifier for electromagnetic energyharvesting: development path and future outlook,” Proc.

IEEE, vol. 102, no. 11, pp. 1667–1691, Nov. 2014.2K.Niotaki, A.

Collado, A. Georgiadis, S. Kim, and M. M. Tentzeris, “Solar/electromagneticenergy harvesting and wireless power transmission,” Proc.

IEEE, vol. 102, no. 11, pp. 1712–1722, Nov. 2014.3About renewable energy available online on the Natural Resources Canada: http://www.nrcan.

gc.ca/energy/renewable-electricity/7295#solar.4T.Barton, J. Gordonson, and D. Perreault, “Transmission line resistancecompression networks and applications to wireless power transfer,” IEEE J. Emerging Sel. Topics Power Electron.

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3160–3171, Jul.2016.6Y.Huang, N.

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64,no. 7, pp. 2146–2158, Jul. 2016.8M.D.

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986–993, Apr. 2014.12  C. Song et al., “Matching network elimination inbroadband rectennas for high-efficiency wireless power transfer and energyharvesting,” IEEE Trans. Ind.Elect., Dec.

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