Design Of Passive Optical Receiver In Visible Light Communication System

Visible light communications(VLC)is a popular study in the field of communications technology.The technique has many advantages:you can use it in a wide region,no bandwidth restrictions,without interfering on radio spectrum,no electromagnetic radiation,high data rates(up to 1Gbps)and so on.These competitive advantages have made people from scientific research to industrial production had a strong interest in it.Due to the specific communication of visible light in space,and it can be used as signal carriers of characteristics,makes the technology to replace the existing optical fiber transmission and electromagnetic wave-mediated signaling,will be widely used in wireless transmission network in the future.Silicon photocells are a commonly used photovoltaic device.It can turn the optical signal into an electrical signal without external energy supply.This paper is based on this characteristic of Silicon photovoltaic cells,use Silicon photocell receiver detectors for visible light communication,receiving and detecting visible light signal internally and converts it into electrical signals for output.And the optical signal gathering energy,similar to cell circuit by the way of confession,realized the passivity of the receiving module.Circuit parts processe the energy and signals separately,completed the receiver for visible light signal data received.This paper presents a passive integrated Visible Light Communication(VLC)receive module based on silicon photocell.Silicon photocell can detect and convert the optical signal into electrical signal without additional energy supply.With this characteristic,we use it as VLC receiving device for passive detection and transmission of optical signals in space.It’s expected to be widely used in optical labels and Internet systems in future.The circuit is designed with TSMC 0.18-μm standard CMOS processes.The photocell works in the illumination of 500lx,it can provide power management with 2V input voltage and 1.8V output.The 3dB bandwidth of the receive part is 67.2 kHz.Output of the overall chip is 0-1.8V standard digital signal,with area of 615x460μm~2.Static power consumption of the circuit is about 1.5m W.