The filters based on coupled resonators, have been certainly the most used narrow band bandpass filters, both in the input and Fi stages in radio frequency applications due to their simplicity, their easy adjustment and above all their low cost. On the other hand, there are not many procedures for their calculation in the specialized literature; and in those that are approached, it is done in a very simple way. This is due to the fact that it is not easy to establish a calculation procedure similar to that of Darlington filters and, therefore, numerical optimization procedures are usually used for their design.