Wireless Mobile Charging is Possible

Well, yeah that's true... Charging your mobile without any wired charger..!! It's possible. Let us see how?

Well, we know, mobiles are using electromagnetic waves for wireless communication. Now what if we use the same electromagnetic waves (EM waves) to CHARGE our mobile? This is possible, it's tough but possible.

Here is the idea:

Ambient EM waves are always roaming around us 24x7. So if we somehow manage to capture those EM waves then they can be used to charge the battery of mobile or any other device.

Now how to capture EM waves? It can be captured by following components.

• Antenna (with vast bandwidth and extremely high gain) 
• Impedance matching circuit (to match impedance between Antenna and Coax cable)
• RF(AC) to DC convertor: (To convert High frequency RF signals to DC signal for charging)
• DC to DC convertor (to amplify the voltage of RF signals)
• Charging circuit (circuit used to charge battery)
• Battery (this component should supposed to be charged)

Figure 1: Block Diagram of Wireless Mobile Charger

Now, hope this block diagram has made clear picture in your mind. Now the key challenge in this is to fabricate an antenna which can capture sufficient amount of power to charge (mobile) battery.

I have tried creating such antenna but unfortunately it was not manufactured up to the mark. But if you really are interested in jumping into this project I can give guidance for fabrication. Basically an antenna should have

• Wide range of bandwidth (ideally 10 Hz to 100 GHz), which is difficult. But if one can cover large of the industrial range of bandwidth than also antenna can gather enough power to light an LED or so. (I had covered GSM (900 MHz) and ISM (2.4 GHz) band).
• Extremely high gain for desired range of EM waves.
• Compact size (challenge)

 Figure 2: Fabricated Folded Shorted Patch antenna

Shown in above figure-2 is Fabricated Folded Shorted Patch antenna, which has S11 (return loss) as shown in below figure.

Figure-3 S11 (return loss) parameter

 

The software used to simulate the return loss and other parameters is either "CST microwave Studio" or "HFSS".

Once the antenna is simulated using above mentioned software and fabricated you have to go to the next step i.e. to match your antenna with coaxial cable. That can be done by putting BALUN. Next we have to convert this RF signal to DC signal because Battery can only be charged with DC power supply. For that we can use multi stage voltage doubler. 6-stage voltage doubler as an example is shown below. Results of this voltage doubler were estimated through multisim simulator software.

Figure 4: 6 Stage Voltage Doubler design in multiSIM

Now, DC to DC convertor is used to stabilize the DC output and give desired gain in terms of voltage.

Note: Here if we increase the voltage using voltage doubler, its current gets reduced. Because power to the input of voltage doubler should be >= output of the voltage doubler (energy conservation). 

At last mobile charging circuitry and battery itself to charge the mobile.

I hope this post has given some information about wireless mobile charging. In fact Mobile Company Nokia is also doing research in this field and it's also expecting some positive results after some years. Let us see whether they can implement it or this is just an idea.

Catch you later..Till then stay tuned and keep on visiting this blog, because lots of new innovative ideas are going to be posted over here. For more information regarding this project you can drop me at my email ID.