Broadband Millimeter-Wave Frequency-Scanning Continuous Transverse Stub Array Based on SIW

A broadband millimeter-wave frequency-scanning array based on substrate integrated waveguide (SIW) is proposed in this paper. The radiation element is stepped continuous transverse stub (CTS) composed of SIW. The fed structure is a grounded coplanar waveguide (GCPW) to SIW transition line using coupling slots. The beam steering direction varies with different frequencies within the working bandwidth. One 16-element array is simulated to validate the design. The simulation results show that the relative bandwidth of S11 less than −10dB is 37.8% from 32.6 GHz to 48.1 GHz. The gain at the broadside is 18.39 dBi with the first sidelobe level of −10.2dB and the 3 dB beam width of 5.6°. The scanning angle range is from −37° to 18° depending on frequency.