Side lobe suppression for X-band array antenna using Dolph-Chebyshev power distribution

This paper deals with the development of X-band array antenna with side lobe suppression implemented using Dolph Chebyshev power distribution. The array antenna which is fed using proximity coupling is intended to work around frequency of 9.3GHz for frequency-modulated continuous-wave (FMCW) radar application. The proposed antenna array consists of 5 microstrip patch antenna elements deployed on a grounded 0.508mm thick RT/Duroid® 5880 dielectric substrate wherein each antenna element is designed with a slot to obtain 90° rotated linear polarization. From the characterization results, it shows that the array antenna has shows side lobe level (SLL) around 20dB at frequency of 9.3GHz with simulated and measured return loss of 54dB and 30.45dB, respectively. Meanwhile, the simulated and measured gains at frequency of 9.3GHz are 12dBi and 11.39dBi, respectively. The result proves that the array antenna design by using Dolph-Chebyshev power distribution is appropriate for FMCW radar applications compared to the array antenna with uniform power distribution.