Abstract: A structure for an infrared ray communication device placed over a lane which encloses a wireless infrared communication device and includes an upper cover for an attachment lens, an attachment lens, a rain shield, a light guiding device, a fixed support for an emitting module, a fixed support for a receiving module, a circuit board socket, a trough for a transformer, fixed hooks, and a rain shield. The device is placed over a path of a passing vehicle, and used to receive infrared rays and to proceed with data transmission.

Abstract: An innovated transimpedance amplifier circuit consists of a buffer circuit, a simulation resistance circuit, and an amplifier circuit. The buffer circuit for inputting a signal circuit is constituted by two FETs and a resistor, and has a high current input efficiency and function of widening circuit frequency band. The simulation resistance circuit is constituted by a resistor, two buffer units, a coupling capacitor, and a biasing resistor. When operating at a low frequency, the simulating resistance circuit permits a large amount of background DC to flow through; on the other hand, when operating at a high frequency, this circuit can improve the signal coupling efficiency and reduce foreign signal output voltage. On the whole, by the circuit of the present invention, both the detecting sensitivity and the amplification factor of the signal current can be significantly improved.