ENEE417 Microelectronics Design Laboratory


The goal this semester is to design, simulate, and realize a wireless microphone system, and the signal is transmitted by using optical pulses over free space. A typical commercial wireless microphone uses transverse electromagnetic wave in UHF or VHF bands. To avoid absorbing too much radiation from the transmitter, and the interference with other electrical signals, we have chosen to use light.


The basic idea is to start from a microphone. The audio signal is encoded by either pulse width modulation, or by frequency modulation. The output is then amplified for driving a light emitting diode. The optical pulses from the light emitting diode transmit over free space and are picked up by a photodiode. The photocurrent is amplified first, and then decoded and amplified yet again for driving a speaker.


The reports are listed below.

  1. FM approach
  2. PWM approach
  3. LED driver
  4. Photocurrent amplifier
  5. Audio power amplifier