C‐band frequency‐scanning continuous transverse stub array with high gain and low sidelobe level

Abstract

A C‐band substrate integrated waveguide based frequency‐scanning continuous transverse stub (CTS) array with high gain and low sidelobe level (SLL) is presented in this paper. The newly suggested linear source generator (LSG) consists of a feeding probe, a main reflector, a sub‐reflector, and two metal matching vias. By introducing one matching via on the left side of probe and another one on the right side of the sub‐reflector, a broadband LSG is obtained to excite the CTS array with a wide scanning range. The operating mechanism of the two matching vias is analysed. In order to reduce SLL, a serial‐fed array with asymmetrically distributed stub width is designed according to Chebyshev distribution for the first time. A prototype of 12‐element array is designed, simulated and measured, and excellent agreements are achieved. The measured beam‐scanning range is from −52° to 2° within the operating frequency of 5.6–8 GHz, in which |S11| is less than −10 dB. The maximum gain is 22 dBi and the SLL varies between −21 dB and −18.2 dB. The proposed design approach can be applied to other bands and other level distributions. The proposed frequency scanning array has great potentials in radar and detection systems.