CPW-Fed Printed Antenna Array With Conical Beam

A printed antenna array with conical beam is presented. Coplanar waveguide (CPW) is used to feed the antenna. Loop slots with finite width of ground plane, which play the role of radiating elements are arranged collinearly to form a traveling wave antenna array. The widths of the loop slots are adjusted to achieve low sidelobe performance. The design procedures are proposed and a 16-element array with beam-pointing angle of 77° is fabricated and measured to verify the design. The measured 15-dB return loss bandwidth is 11.4% at central frequency of 10.5 GHz. The measured gain and the sidelobe level are 10.3 dBi and $-20\;\text{dB}$, respectively. The agreement between the measured and the simulated results is acceptable.