From Wesley: Special Thank you
speedy125PART#4
IMPORTANT!!
speedy125 send link:This work was supported in part by the Guangdong Natural Science Funds for Distinguished Young Scholar under GrantTitle:
Title:
Wireless Energy Harvesting by Direct Voltage Multiplication on Lateral Waves From a Suspended Dielectric Layer
Link:
https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=8053760From part #1 we have learned that
-earth as multilayered part of interface is suggested.
-that is in line with Marconi’s early experiments,
-the paper explores the feasibility of wireless energy harvesting by direct voltage multiplication on lateral waves.
-we could also look at picture representing multilayered interface
- we had the first look at wave behavior while "loading" into interface
From part #2 we have learned:
- the differences between regular EM wave known also as Space wave and Surface wave.
- the 4 layer suggested ground as one of parts of interface Air/Earth
- the wave in the interface must be in TM mode
From part #3 we have learned:
- that the thickness of both layers of the interface is expected to be 1/4 of the wavelength Y
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V. HARVESTING ENERGY FROM LATERAL WAVES BYDIRECT VOLTAGE MULTIPLICATION
In one of Tesla’s lectures [18], Tesla has highlighted the fact that power transmission
by one-wire transmission line is equivalent to wireless power transfer. Although the link between
power transfer by one wire and wireless power transmission has not been well explored in other research literature,
it was found in a recently published work [21] that the energy from a time-varying electromagnetic field can be
captured by a one wire transmission without any antenna.
In this work, wireless energy is harvested from lateral waves on the surface of a suspended dielectric layer
using a little known open-ended voltage multiplier.
Fig. below illustrates the schematic diagram of the open-ended voltage multiplier similar to the one proposed in .
This open-ended voltage multiplier has an input terminated by an open-circuited Goubau line.
Goubau line is one-wire transmission line having characteristic impedance very close to the characteristic
impedance of free space.
If the end of the Goubau is left open-circuited, it becomes a monopole antenna which captures ambient electromagnetic field right
on the top surface of the suspended dielectric layer without any other form of antenna.
The voltage sensed by the Goubau line is rectified into at DC voltage using the well-known Avremenko’s diode configuration formed by diodes
D1 and D2 [22], [23]. Thevoltages across D1 and D2 are very limited because each of the diodes has its own maximum forward voltage.
However, before reaching the output, the voltages across D1 and D2 can undergo voltage multiplication by the differential voltage
multiplier formed by diodes D3,D4,D5 and capacitances C1,]C2,C3 and C4.
The output voltage is the sum of the voltages of all the diodes D1-D6.
The fundamental AC voltage across D1 and D2, 2V D, depends on the time-varying electromagnetic field
captured by the Goubau line, which cannot be changed by changing the circuit topology.
However, the AC voltage across each of all other diodes D3-D6 can be force-increased to a maximum of 2VD by introducing the AC shorts formed
by capacitors C1-C4.
All the diodes used in this circuit are assumed to be the same and all the discrete capacitors used in the circuit are assumed to have a capacitance C.
If the parasitic inductance Lp is sufficiently small, then the output voltage can be derived and approximated using the approach given in Appendix I
n is the intrinsic ideality of the diode.
Is is the reverse saturation current of each of the diodes.
nKT/q is the threshold voltage, which is typical 25 mV at room temperature.
f is the operating frequency.
The formula given in (16) assumes that the load resistance is infinitely large.
The last term of (16) also accounts for the frequency dependent effects due to the capacitances in the layout.
The prototypes for the proposed open-ended voltage multiplier have been fabricated on a
Rogers Duroid (TM) substrate 4350B with thickness=1.52mm.
Fig. 2 shows the details of the proposed open-ended voltage multiplier.
The diodes used for fabricating prototypes in this work were
SMS7630-093 from Skyworks. The schematic diagram, the photo of the fabricated prototype and the simulated electric field distribution
at 1.24 GHz are respectively shown in Figs. 2a, 2b and 2c.
The input impedance of the opened voltage multiplier was approximately 400 ohm according to electromagnetic
simulation.
It should be noted that, for the purpose of verifying the design against the simulation,
the output voltages of the proposed voltage multipliers were first measured as a function of frequency
when the input terminals were fed with a 50 ohm microwave power source
(E8267D, Agilent Technologies) at 20 dBm.
The measured results together with the results of layout/schematic co-simulation done using
Keysight’s Momentum are shown in Fig. 2d.
Wesley