Signal manipulation through horn antennas loaded with metamaterial-inspired particles: A review

This review paper summarizes our latest results on designing metamaterial-inspired particles that can be inserted inside horn antennas to provide signal manipulation capabilities to the overall system. Metamaterial-inspired band-pass filtering modules, based on the use of either bi-omega particles or complementary electrically small resonators, are firstly presented. The bi-omega particle enables the antenna to perform filtering operations on the received signal to radiate/receive only the narrowband signal of interest, improving, thus, the signal-to-noise ratio. The second module, besides filtering the unwanted signals out, allows converting the linearly polarized mode of the feeding wave-guide into a circular polarized field in the horn, and vice-versa. Moreover, some band-stop filters, based on the employment of single or coupled metamaterial-inspired resonators, are presented. All these components are of extremely compact size and, therefore, can be easily realized with standard PCB technology and added to standard horn antennas to increase their functionalities.