We want you to speculate about a circuit design, to budget for device costs and performance.
The circuit uses patch antennas which are designed to absorb and harvest the energy from a specific Bluetooth channel.
Bluetooth 5.0 is now in iOs 8 and 10 phones.
Now any iOs 8 or 10 can be a beacon, with unidirectional data, unconnectable, with periodic advertising being sent a fixed intervals.
Bluetooth allows broadcasting on a single channel, for example, only Channel 37, or only Channel 1.
The radiation from a Class 2 Bluetooth device is nominally 3 dBm, which converts into approximately 1mW.
I want you to speculate about a circuit comprised of simple components like resistors, capacitors etc. which will modulate the harvested energy from the Bluetooth signal into a signal suitable to drive a single lcd pixel, with a turn on voltage of 3.5V.
Bluetooth channel 37 has a 2.402 Ghz frequency, 2,402,000,000 pulses.
A single analog lcd pixel is optimized at 44 Hertz, square wave signal, 3.5V
The mobile device could emulate the lcd signal, by emitting approximately 30 mHz pulses, followed by a 30mHz long pause, and then another 30 mHz pulses, followed by a pause, etc.
The 30 mHz pulses from the mobile device would approximate a single pulse of a 44 Hertz signal.
The analog lcd pixel would consume the Bluetooth signal is if it were a 44 Hz signal (44 x 30 mHz + 44 x 30 Mhz = 2402 mHz) approximately.
I want you to speculate about a circuit which would optimize this energy harvesting.
We can use dozens of resistors and capacitors for the design.
Can you speculate a circuit which would allow the mobile to drive the lcd pixel directly, without using transistors?
Can you speculate about a circuit which would have transistors? A battery would supply electricity to the circuit. Antennas designed to absorb a specific Bluetooth frequency would supply power to a transistor, which would be the logic gate.