| 摘要 |
PROBLEM TO BE SOLVED: To attain a combination of channels that is optimum to secure the satisfactory crosstalk characteristic by setting the number of channels of an optical multiplexing device of every stage at an integer close to N<1/n> in terms of a principle with each other when N and n show the total number of channels and the number of connection stages respectively. SOLUTION: The number of channels where only an array lattice filter 11 having 5 channels is placed out of band among those channels which pass the outside of a pass band just once is equal to the number of filters serving as pass bands of other array lattice filters and therefore defined as 30/6-1=4. In the same way, the number of channels where only an array lattice filter 12-i having 6 channels is placed out of band is defined as 30/5-1=5. In other words, the number of crosstalk channels is 9 in all. Then an array lattice filter of 30 channels has 29 crosstalk channels, i.e., 20 crosstalk channels decrease. In cascade connection, the number of channels of every stage is defined as a combination of integers 5 and 6 close to 30<1/2> =5.47. Thus true crosstalk characteristic is improved. |
