https://pdfs.semanticscholar.org/b10d/b093ac542dee9144d311231f7ab7d042f2c9.pdf

A filtering antenna can incorporate a filter that removes part of the band the antenna would otherwise receive. This can be useful if there is strong interference there, for instance.

Hi Dhivya Priya E.L.

Hope these articles will help you:

Conference Paper Filtering antennas: Comparison of different concepts

Article Review of Recent Developments in Filtering-Antennas

Regards

You have to learn first what is antenna and why we need that in communication system. Then you have to learn what is filtering. And how it is included in antenna to work as filtering antenna.

If I'm going to write each things here, then it would become one chapter of book.

If you still need help, feel free to contact me through whatsapp at +918200713617.

filtering antenna or filtenna is a filter + antenna in the same structure.

"Practical implementation of real-time cognitive radio energy detector using frequency reconfigurable filtenna"