CX Band Semi Disk-Ring Dual Band Shared Aperture Antenna

An efficient simple design of a dual band low isolation shared aperture antenna is presented in this communication. The design consists of a semi disk placed in between a circular ring with a two port network. The S-parameters have shown good response of -40 dB in the band with a directivity/gain of about 7.8 dBi. The side lobe levels have been reduced to an ultralow level of -29.1 dB. The designed antenna resonates in C and X frequency bands and the isolation is as low as -35 dB and -45 dB respectively at the two resonating frequencies.