Abstract :
The introduction of filter coupling has allowed new complex systems to be brought into operation on complex sites and in close proximity to existing systems without any degradation in the performance of either system. There are also great ecological advantages in the reduction of the number of antennas on radio sites which enables additional systems to be added without building further structures. The increase in background noise brought about by the increase in the number of emissions together with the broad band noise produced by semiconductors has necessitated the use of filters generally and by simple addition of coupling structures these filters have been up graded into multicouplers. This will be a continuing trend and the industry must seek the most economic methods of producing such systems with yet further improvements in the technical parameter
