Design of a low profile phased array filtenna with frequency agility and wide spurious rejection band

In the present work, the design of an X-band low-profile phased array antenna with inherent frequency selectivity properties is presented. While the radiating element consists of a slot-fed-patch antenna, the filtering function is carried out by a band-pass filter integrated in the antenna panel. An effective technique for the rejection of spurious resonances is also described. This is achieved by detuning the corresponding harmonics of the radiating element and filter, as a result of the perturbation of the higher order modes' currents on the patch. Furthermore, frequency reconfigurability is introduced at antenna level in order to extend the operational bandwidth from 8.5 to 10.5 GHz.