A multibeam antenna array at P and L bands is proposed，covering the 90°space range in the azimuth. The multibeam can be acquired by phase shifter network that consists of analog delay lines，and the phase shifter network is integrated with power divider network by using miniaturization techniques. The phase shift values are realized by Printed Circuit Board(PCB) process. The Radar Cross Section(RCS) reduction of the antenna array is realized at X and Ku bands，by adopting Log Periodic Dipole Antenna(LPDA) element and pasting the absorbing material to the bottom surface of the array installation. Theoretical analysis and measurement results show that the array is with the features of broadband and multibeam radiation pattern. At the same time, the average RCS is less than 16 m2 within 180°space in the azimuth, which satisfies the requirements of the system design.