RF radio frequency engineering electrical engineering electronics energy harvesting

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Manish J.UMESH K.Dilek I.Parul G. have already sent a proposal.
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Experience Level: Intermediate
Electrical Engineering Posted 3 hours ago
This project examines a circuit, verifies its feasibility, and possibly suggests alternate circuits which are optimum.

You have lots of knowledge about antennas, microwave energy, energy conversion, and the math to calculate optimized circuits.

In this system, Bluetooth energy is broadcast on a single Bluetooth channel, say channel 39. The energy is absorbed by a planar patch antenna which has been configured to absorb energy at channel 39. The received energy is modulated to directly drive a single lcd pixel. In essence, the mobile phone energy multiplexes the lcd pixel.

You will study the circuit, prove the feasibility of the circuit with mathematics, and possibly suggest more optimized circuits.

Here are the facts so far :

I attached a TI RF Bluetooth dongle to one computer as TX, and another TI dongle to another computer as RX.

The TX dongle broadcast at channel 39, at 5 dBm power. The RX dongle measured -30 dBm power. Class 2 Bluetooth devices are 2.5 mW (4 dBm).

A single lcd pixel is optimized at 44Hz, about 20 MICROamps of power (or less), 2.5V-3.5V or higher. 20 MICROamps, not milliamps.

We "print" antennas and organic electronic components on a printing press on plastic film. We can print resistors, capacitors, inductors, and simple OFETS.

We like to use ordinary polyester film. In your reply, please suggest the best film thickness in microns. Typical thicknesses are 12 microns, 25 microns, 38 microns, 50 microns, etc.

For conductor we like to use PEDOT/PSST and vacuum coated aluminum. For packaging, vacuum coated aluminum is usually about 50 nm thick. It is possible, but not common, to coat aluminum in thicker coatings.

iOs 8 and 10 both provide support for BLE 5.0, aka Bluetooth 5.0. We have not looked at these phones yet for feasiblity. However there are already programs at iTunes that turn ordinary phones into Bluetooth BLE 5.0 beacons.

Here are the drafts of the milestones :
Milestone 1 : Write up the mathematics proving the adequacy of the circuit to drive a single lcd pixel, without using a battery.

Milestone 2 : List the optimum thickness for the film, the aluminum coating thickness, estimate the approximate dimensions of the antennas, and the approximate dimensions of the inductor and band pass filter. Estimate the number of antennas to achieve a voltage of about 2.5V-3.5V, 10-20microamps for the lcd pixel.

Milestone 3 : Suggest changes, further refinements, improvements to the alternate energy harvesting techniques in the drawing.

Optional Milestone : Find or determine the Bluetooth energy output of an iOs 8 or 10 phone. Broadcom BCM4361 in the Universal Scientific Industrial (USI) 339S00397 Wi-Fi/Bluetooth module? BCM4375?
http://www.usish.com/english/products_wifi.php https://community.broadcom.com/welcome

Optional Milestone : Draw the antennas array, bandpass filter, inductor.

Define PWM in 1-3 short sentences?

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Clarification Board Ask a Question

  • Simon P.

    Although you project sounds interesting, there are numerous technical challenges to it. There are studies relating to this field including PHD Thesis.
    Do you realize -30 dBm is 1uW? so if the LCD uses 1uA, there isn't sufficient power to maintain illumination. (Energy harvesting is designed for short bursts with long periods of inactivity). ePaper might be better, but again, available power is an issue, updates must be infrequent...

    I would be happy to work with you on this, but it requires expert help in some areas.
    Give me an invite if you want more.


    P.S. PWM: A modulated signal varying the mark/space ratio often used to achieve a digital to analog conversion of voltage. (and NOT what you want to use here!)