Design of multifunctional instrument of insert loss and return loss measurement

A new kind of insert loss and return loss measurement system was developed to improve the precision and speed of the measurement.The new system was made of optical unit and circuit unit.Optical couplers were used to get the loss power of optical connectors,and the power was transformed into electric current by detectors.The current was received and then amplified and transformed into digital signals by circuit unit.A single chip was used to calculate digital signals and output the result to the LCD.The experimental results show that the system is able to display the return loss and insert loss immediately with at the precision of 0.05dB.Further,the result indicates that the high precision measuring range can reach 70dB.