The ever increasing demand for
the energy has led to the search for the alternative sources for it. One
solution to this is the exploration of ambient sources of energy. There are
numerous available sources of energy in the environment that can be harnessed;
the sources are in the form of vibration, solar, and Electromagnetic (EM) waves
or 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 hand
the EM wave is always available. Over the past few years there has been tremendous
growth in the Internet of things (IoT) domain which encompass the mobile base
station, 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 the
energy contents are very less in amount. One major motivation towards this is
that 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 the
energy need of the mankind.
to 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 potential
research domain for the energy need exploration 1.
Fig. 1. Block diagram of RF energy harvesting
*(PMM: Power management module)
Fig. 1 shows the general scheme
for the Energy harvesting system. The antenna picks up the signal from the
ambient and fed to the non-linear block which is generally comprised of the Schottky
diode to convert this into the dc. It is then followed by a filter that
eliminate the ripple contents 2, 4. Finally, it is stored or utilized to
power the low power IoT devices. Antenna is followed by an impedance matching
network, this block is very important with respect to the maximum power
transfer 5-6. Its purpose is to match the impedance of antenna to the
complex impedance of the rectifier over a broader band of frequency range thereby
maximizing the power content and signals dynamic range. The storage element and
the power management module (PMM) present an optimum load for achieving high
efficiency. Recently, the power amplifier (PA) based configuration has gained
increased 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 ascribing
this to the very low level of available RF signal, it therefore necessitates to
achieve high efficiency in such system. Not least, the location dependency and randomness
of the sources exacerbate the task 1. In this context, many research have
been reported which are based on the optimization process than on the
analytical methods. Till now, the reported schemes have only achieved an
efficiency 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 concurrently
from two frequency sources have also been reported 2, 14 but it is limited only
to the lower frequencies as the lumped elements constrain its use at higher
frequencies. Impedance compression technique is also limited to higher ambient
power source regions 4. The PA based system is still in the development as it
requires higher power level than available 8-9. Therefore, in order to successfully
harness energy it is imperative that efficient RF energy harvesting schemes be
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 based
within the university and at other universities may also be required. Finally, it
will finish with publications and reporting etc. The above mentioned steps can be
break into two levels, Master and PhD.
It mainly involves the courses study to make a stronger foundation.
Below are the subjects that need to be studied for it.
Analog CMOS circuits
RF circuit design
Digital Signal Processing
In parallel, literature survey and research thesis based on the
planned research is to be followed. Some research are to be published. Finally,
a thesis report based on the research is to be prepared.
After having strong theoretical knowledge at Master level with research
background, a full fledge research for the implementation of the planned
research is to be carried out. It involves the below listed steps.
Diode-based highly efficient rectifier design, prototyping and measurements.
Highly efficient PA rectifier design in collaboration with other
departments, fabrication and measurements.
Effective Antenna design, fabrication and measurement
management module design in collaboration with other departmental faculties. Final
system integration, measurements.
Paper writing (IEEE Journals: TMTT, MWCL, TCPMT, TCAS-1 & 2)
and presentation at top Conferences (IEEE IMS, WPTC, EUMC, MWSCAS)
Hemour and K. Wu, “Radio-frequency rectifier for electromagnetic energy
harvesting: development path and future outlook,” Proc. IEEE, vol. 102, no. 11, pp. 1667–1691, Nov. 2014.
Niotaki, A. Collado, A. Georgiadis, S. Kim, and M. M. Tentzeris, “Solar/electromagnetic
energy 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.
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compression networks and applications to wireless power transfer,” IEEE J. Emerging Sel. Topics Power Electron.,
vol. 3, no. 1, pp. 252–260, Mar. 2015.
Song et al., “A novel six-band dual CP rectenna using improved matching
technique for ambinet energy harvesting,” IEEE Trans. Microw. Theory Tech., vol.64, no.7, pp.3160–3171, Jul.
Huang, N. Shinohara, and T. Mitani, “Impedance matching in wireless power
transfer,” IEEE Trans. Microw.
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broadband rectennas for high-efficiency wireless power transfer and energy
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energy-conversion efficiency for energy-harvesting circuits under
power-optimized waveform excitation,”
IEEE Trans. Microw. Theory Tech., vol. 63, no. 5, pp. 1758–1767, May 2015.
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