This paper developed a simplified design of broadband metamaterial absorber (MA) covering X- and Ku-band. Based analysis of its equivalent circuit model, this paper moves a step forward in terms of using COMSOL simulation software to optimize and analyze the structure parameters of the MA. The simulation results show that the absorptivity of the designed MA at the entire X- and Ku-band (8 GHz-18 GHz) is more than 90% under normal incidence for both transverse electric (TE) and transverse magnetic (TM) polarization, and with good absorption characteristics under a wide incident angle. Furthermore, compared with the previous reports, the MA designed in this paper with simple structure, and without consideration of loading lumped elements or using new materials, the absolute and relative bandwidth reach up to 10 GHz and 76.92%, respectively. This study can be applied to reduce radar cross-section, stealth and improving the electromagnetic compatibility of devices.