Compact Phased Array Antenna Integrated With CRLH Based Digital Phase Shifter for X-Band Radar and Satellite Communications

This paper presents a new compact planar phased array antenna for X-band radar and satellite communication applications. For designing the antenna array, linear 4-elements circular patch using aperture coupled feeding was utilized. The array is combined with a novel composite right/left-handed (CRLH) metamaterial phase shifter. In this work, the phase shifter is designed to obtain digital phase bits of $5.625^{\circ}, 11.25^{\circ}, 22.5^{\circ}$, and 45° by cascading CRLH unit cells. The phase shifter exhibits low insertion loss of <1.87dB at the center frequency 10 GHz with return losses >10dB. The proposed phased array exhibits a peak gain of 7.81 dBi, whose radiating beam can be steered over different scan angles ranging from -16° to +14°. At the highest scan angle, the side lobe level is $\lt _{-}$11.4dB, and the co-to cross-polarization isolation is >22.4dB.